key: cord-0006391-4hxa6vvw authors: nan title: European Nuclear Medicine Congress: August 14–17, 1984, Helsinki, Finland date: 1984 journal: Eur J Nucl Med DOI: 10.1007/bf00276467 sha: 6d0a5e5d30be7be09885629154b58d201384dac1 doc_id: 6391 cord_uid: 4hxa6vvw nan In order to assess the interest of exercise single photon emission computed tomography by thallium 201 (SPECT) in patients with suspected isehemic heart disease (IHD) ]59 patients (M : 148, F : ]I, mean ~ge : 52 ! 8) were submited to the following protocol : l) SPECT after an injection o~ 2.5 mCi of TI 201 at maximal exercise 2) Coronary angiography performed within I month before or after SPECT. Methods : SPECT allowed the reconstruction of three types of slice according to the long axis (LA) of the heart which are called as in 2 D-Echocardiography : short-axis (perpendicular to LA), long-~xis (parallel to LA), 4-chambers (parallel to LA) slices. The myocardial fixation was analysed in 5 walls (septal, anterior, lateral, inferior, Apex) by two independent observers who did not know angiogram results. Material : ]26 pts with IHO (coronary stenosis ~ 50 %) divided as follows : 63 one vessel disease (L.A.D. : 32, R.C.A. : 2~, LC.X. : IO), 37 two vessel disease (2 VD), and 26 three vessel disease (3 VD). 33 pts without coronary steresis : 26 Normal (group A), 7 pts with normal coronary arteries and angina or prior myocardial infarction. In conclusion : Exercise SPECT has an overall sensitivity of 96 % and an overall specificity of 85 %. This allows us to consider it at the moment as the best non invasive method for the diagnosis of I.H.D. To determine the clinical impact of scintigraphy in coronary artery disease (CAD)~ the indications, diagnostic yield and contribution to patient management ~ere reviewed retrospectively in 105 patients referred for routine investigation, f×ercise and redistribution image data ~ere collected in multiple projections and inferpreted by visual and semi-quantitative means. A segmental image defect ~ss accepted as indicating the presence of CAD. Ii-201 sc~ntigraphy ~ss performed as a diagnostic procedure in 71 patients (69,~) ~ho had equivocal evidence of CAD. In 57 (80,%) of these patients, ~i-201 scintigraphy was ~ormal and 53 (75,~) ~ere spared diagnostic coronary srteriography, Despite normal If-Z01 seintigraphy, arteriography ~as performed in 4 patients ~ith persisting symptoms and demonstrated normal vessels in 2 patients and single vessel disease in 2 patients. Conversely, arteriogrsphy ~ss normal in 3 of 19 patients (16,~) ~ith unequivocal image defects. Ti-201 scintigraphy ~as performed as a Functional complement to coronary srteriography in 32 patients, influencing the decision for coronary surgery in 10, for sngioplmsty in 9 and against surgery in 2. Myocardial ischaemia ~as confirmed in 8 and refuted in 8 patients ~ith questionable arteriographic coronary disease. Positive management decisions ~ere taken as a result of [i-201 scintigraphy in 80 of these 103 patients (78%). These data confirm the vital role of TI-201 sclnfigraphy in the evaluation and management of patients with suspected and proven CAD. The value of thallium-201 exercise scintigraphy for the detection of multivessel disease after myocardial infarction (MI) was determined in 176 patients 6 weeks after a first MI. In all patients coronary arteriography was performed within 3 days after the noninvasive procedure. Of the 176 patients, 77 had multivessel disease (prevalence 44%). The thallium-2Ol scans were qualitatively assessed, and a positive scan was defined as an exercise-induced reversible defect in the noninfarcted region. The exercise electrocardiogram was positive in 49 patients (sensitivity 64%), while the thalli~m-201 scan was positive in only 24 patients (sensitivity 31%). When the results of both exercise electrocardiography and scintigraphy were added, a sensitivity of 66% and a specificity of 62% was found; the positive and negative predictive values were considered too low for accurate diagnosis of rnultivessel disease in patients after MI. We conclude that the qualitative assessment of thallilun-201 exercise scintigraphy should not be used to predict the presence or absence of multivessel disease in patients with previous MI. This study tests the hypothesis that the results of stress TL-201 scans (TL201) are related to the trans-stenotic pressure gradient (GRAD) of coronary stenoses independent of the % lt~ninal ditcher narrowing (%NAR) seen at angiography. The 22 study patients (mean age 46 years, range 30-62, 2 female) had no prior myocardial infarction. Each underwent a symptom limited erect bicycle exercise T1201 test off antianginal therapy, shortly before percutaneous transl~minal coronary angioplasty (pTCA) for isolated left anterior descending coronary stenosis. The %NAn, GRAD (mmHG) at PTCA and presence of TL-201 defects were independently evaluated and results compared. The GRAD (mean+SD) is listed in relation to positive (+) or--negative (-) TL201, and %MAR. In the 18 patients with <90 %MAR, the GRAD was higher (P<.001) in those with +TL201 (64+15) than those with -TL201 (33+20) but their %NAn did not differ significantly (72+14% vs 66+19%; P=NS). At multiple regression analysis (N=22) the presence of a TL201 defect (p<.001) was a strong and %NAn (P<.05) a weak independent predictor for GRAD. Exercise workload, heart rate, blood pressure, and stress ECG results did not significantly predict GRAD. It is concluded that TL201 adds valid information on the hemedynamic significance of a stenosis independent of %MAR. This may be of most value when %MAR is <90% and the clinical significance of the stenosis is uncertain. The aim of the study is to use Ig3I meta-iodobenzyl ~is/lidine [LIBG instead of 1511 MI~G because of its potentially hitcher sensitivity to localize adrendLl medullaz~j and extra-medullary %n~nours 8/Id metastases of phaeocbccomooytoma. MIBG was s~mthesized and labelled with 183I in a closed sys%em. 1 m~m ~[[BG is added to lO mCd dry 1251 in the Ilarwell vial, to this is added 1O0 ~i glacial Acetic Acid, and 5-5 mg ~on-iur~ 81/iphate powder. The vial is sealed end is heated for 45 minutes at 140-160 ° in sn oil bath. After cooling, 1.5 ml 0.005 M Acetate buffer (pH 5.8-4.2) is added. It is then passed throt~h a Cellex-D ion exchange resin oolll~in into ~n evacuated vial via a 0.22 ~/m millex filter. iBbI M]~G Gamma Cg/aera images ~e obtained 4, 22 8/%d 45 hours post injection of 5-5 mot 1251 MIBG. In seven out of eight hypertensives, the normal adfcenal medu/lae were visuslised indicating the sensitivity of the technique; in one patient who had had adrenalectomy for phaeoo~aromocytoma, 125l MI~G showed mu3_tiple livem metastases~ which X-ray eompllt -ed tomography and ultrasou/ld did not detect. In a second patient who had had a chest psmagamglioma excised, 125I M]~G scan detected m~tiple metastases in Ehe skull~ mediastinum~ 3n.ngs and pelvis. All lesions were seen clearly within 24 holt, s. Sointi~aphy with 1251 MIBG gives a lower radiation exposume than 151I MIBG and provides a sensitive and reliable means of locating a wide range of phaeochromocytoma. The adrenocortic~l imaging agent, 1311-6B-iodomerhylnorcholes~erol (NP-g9), has been used ~o scintigraphically depict disease of the adrenal cortex in 490 patients studied over an eight year interval (1976) (1977) (1978) (1979) (1980) (1981) (1982) (1983) (1984) . One mCi/l.73 M 2 was administered to 160 patients with suspected Cushing's Syndrome leg) and to 31 patients with miscellaneous disorders of the inner adrenal cortex. Images were obtained a= 5 to 7 days post injection in this group. Dexamethasone suppresslo~ of pituitary adrenocorticotrophic hormone (ACTH) was given Co 157 patients with primary aldosteronism (FA) and I19 patients with adrenal hyperandrogenlsm (A~): 8 mg for 2 days or 4 mg for 7 days prior to NP-59 and ~hroughou~ a 5 day pose-injection imaging interval. In CS 5 patterns of adrenal imaging were noted tha~ were a direct consequence of the pathophysiologlc process: ACTH dependent CS -bilateral adrenal visualization, ACTH independent CS from adrenal adenoma showed unilateral uptake, while ACTN independent CS due to nodular hyperplasia showed marked asymmetric adrenal uptake. CS due to carcinoma was depicted as bilateral nonvisualization. PA was depicted as early unilateral uptake (< 5 days) in adenoma and bilateral early uptake (< 5 days) in bilateral hyperplasia; while in AH early unilateral viaualizatio~ (< 5 days) was seen in patients with an adrenal adenoma, bilateral early visualization (< 5 days) in patients with adrenal hyperplasia and bilateral nonvisualization in those patients without an adrenal eontrihutio~ ~o abnormal androgen levels. There were 3 false positive studies for adenoma in CS~ PA, and AH and 6 false negative studies for bilateral hyperplasia and adenoma. Thus, AS is an efficacious modality for the localization of adrenal function in patients with suspected diseases of the adrenal cortex. The field of Nuclear Medicine and its practitioners, the physicians and the technician, utilize two primary tools: radionuclides and detection instruments. The early history of Nuclear Medicine primarily relates the development of radionuclides and radiopharmaceuticals. George DeHevesey introduced the tracer concept into biology in 1923. He proved that the amount of radiation needed for tracer studies was so small that the system under study would not be affected. Dynamic flow studies were classically reported by Blumgart and Weiss on the velocity of the circulation in patients with heart disease in 1927, seven years before the discovery of artificial radioactivity by Curie and Joliot. With the invention of the cyclotron I by E. O. Lawrence in 1931 radioiodine, 1-131, became the pre-eminent radionuclide of Nuclear Medicine during its infancy. This review lecture will consider the quality assurance to be maintained in the preparation as well as the use of radiopharmaceutical compounds. We will briefly review all compounds in routine clinical practice and pay special tribute to Tc99m-pertechnetate. Although Tc99m is used in almost 85% of clinical Nuclear Medicine procedures, the remaining 15% that are utilized for special purposes will be considered. Those lesser used compounds such as positron-emitting radionuclides and organ-specific compounds such as iodocholesterol for adrenal imaging will also be considered. The various reporting systems for adverse reactions to radiopharmaceuticals currently being utilized throughout the world will be discussed. Current developments in radiopharmaceuticals will include a discussion of monoclonal antibodies such as In-lll labeled antimyosin, tumor markers, and so forth. The ultimate quality of the data processed by modern gamma cameracomputer systems can only be as good as the standard achieved in the process of data acquisition. The role of the radiographer/technician in the initial data acquisition sequence is vital if errors, artefacts or pit-falls are to be avoided. In this presentation, the authors review the main sources of error and aspects of quality control which need to be taken into account if the best data processing is to be achieved. Within this objective, aspec~ of instrumentation, radiopharmaceutical preparation, hard copy out-put, patient preparation and patient supervision apart from criteria for operator techniques, will be discussed. Phantom and clinical data will be shown high-lighting each aspect of the above mentioned items. Ultimately, Nuclear Medicine data acquisition methods will become progressively automated, liberating the interpreter/physician in the wasteful supervision of the data acquisition process. In this context, the role of the radiographer/technician gains a new status, guaranteeing appropriate data interpretation. A preliminary comparison of 180 ° and 360 ° reconstructions of liver SPECT has shown that an increase of lesion contrast can be obtained for known lesions if an appropriate 180 ~ reconstruction is used. We present here the results of a study involving 52 patients with suspected space occupying disease. ~e aim was to assess the clinical usefulness of the 180 ~ reconstruction and, in particular, to determine if the contrast of small lesions can be enhaBced over the effective threshold determined by image mottle (noise). 18 patients were found to give positive results from 360 ° SPECT reconstruction studies in disagreement with ultrasound performed on the same day. A set of criteria were used to re-evaluate the suspected lesions in these patients. These were: I. If % lesion contrast (LC) is > twice the % standard deviation (SD) of the mean pixel count over normal liver, the l~sion was considered positive. 2. For LC < 2SD, 180 ° reconstruction was performed. 3. If LC > 2SD for the 180 ° reconstruction, the lesion was considered positive. Using these criteria the number of discordant Makuuchi, and N. Okazaki Owing to the recent advancement of echography, angiography, X-ray CT, etc., preoperative study of the liver for various kinds of tumorous conditions is now conducted in connection with the segments. Fortunately, radionuclide imaging apparatus has been improved remarkably in its resolution for the past several years. Consequently, we have come to get interested in liver segments on the ordinary scintigrams as well as SPECT images. We carried out this study from the standpoint of seek~ ing the location of the defects in cases in which the segments having SOL were previously known by other modalities. As a result, we came to a conclusion that, in fairly many cases, precise judgment of the segments on radionuclide images might be possible. In this study, we followed the Couinaud's segmentation. Also found were some incorrect illustrations about the liver segments in the previously published articles concerning nuclear medicine. At present, we think that the ordinary scintigrams and the SPECT images are complementary to each other for segmental assessment of the liver. It can be thought also that the effort to clarify the segments will improve diagnostic capability of the liver in the field of clinical nuclear medicine. In order to establish the clinical value of liver spleen tomoscintigrams in routine medical practice, 200 consecutive patients with clinical and biological suspicion of liver diseases ( known cancer in 82, e~hylism in 117 ) were prospectively screened by hepatic tomoscintigra~hy (TScl. Transverse, coronal and sagihtal slices were in each case performed from ( single head single photon ) -Camera recording realised 10 min. after injection of 5 milliCurie$ of 99mTc colloids. Pictures were systematically analysed without knowledge of clinical data according to precise predefined criteria ( liver sizes, estimated sple nic volume ~ osseous reticulo~ndothelial fixation ,relative splenic hyperfixation, homogenous or heterogenous distribution of the colloidal activity in the liver, presence or absence of non or hypoactive zones I their number, localisation~ size and shape, "dissected" aspect of the slicesly.) A suspected diagnosis was in all cases proposed ( normal~ abnormal -hepatocellular and/or metastatic or primitive tumoral disease I. In 75 % out of the cases, one or more additional investiga~ tions were performed ( Echography~ CT scan or laparoscopy-biopsy ). In first analysis-( normal or abnormal )~ almost no falee negative TSc results were encountered ( high sensitivity ) but results varied according to the kind of disease investigated ( good in hepatocellul~r disease, less in metastatic process )~ A ROC analysis and Bayesian analysis of the images has been performed in order to establish the criteria or ~ombination of criteria allowing the most specific and or sensitive scintigraphdc criteria; From the clinician point of view, it was concluded that liver TSc is a highly sensitive investigation that should be regarded as a non aggressive scree ning test in suspected liver diseases permitting in most cases ~n orientation for luther examinations and in some, a final diagnosis. C.H.J.Bracops~ 79~ rue Dr Huet, Io70~ Belgie. The value of ultrasonography(US),99mTc-sulfur co lloid liver scan(LS) and perztoneoscopy(P) in the diagnosis of malignant focal liver disease (MFLD) has been evaluated cuantitmtively according to a score from -2 to +3 referred not only to tbe intrinsic information(IS) provided but al_ so to its impact on the prevzous clinical impre ssion(CS), and cualitatively according to the sual indexes:sensitivity(Se),specificity(Sp),the predictive value of a positlve (PVP) or negetive (PVN) test and accuracy(Ae).Seventy-seven conse cutive patieats with confirmed MFLD,56 with liver metsstases(LM) ~nd 21 hepat0cellular csrcinoma(HCC) were the study group.One hundred and twenty consecutive patients with diffuse liver disease(DLD); ii acute hepatltis,14 fatty live~ 24 chronic hepatitis and 71 hepatic cirrhosis were the control group.The results are shown in the Two hep~tobiliary(HB)agents, dilnethyl-IDA(HIOA) and p-butyl-IDA in form of instant kits produced in our department were subjected for a comparative biokinetie study in animals and human beings. The organ distribution data of the HB agents in mice showed substantial differences in the extent and rate of HB clearance and kidney uptake. The animal studies indicate that they are not in the same group of HB ~xcretmres as man. The in vivc plasma binding with both HB agents were determind by recording the activity of the columns(GCS-profiles)with a gamma camera. The high affinity of p-butyl-IDA to plasma protein, is probably influenced the rate of HB excretion into the bile.To the normal subjects NIDA and p-butyl-IDA were given in a dose of 5-TmCi, and the dynamic study was performed under gamma camera. To 19 individuals,7 patients were given HIDA and the rest were given p-butyl-IDA. Sequential scintigrams in a supine position were recorded every 5s/frame for the first 2min and a 30s/frame for the rest SCmin. Rectangular regions of interest were flagged,and the histograms were computed. In normal subjects, the duration of kidney visualization,early and late hepatic pictures,time of begininq visualization of bile duct and gallbladder and the appear= ance of agent in the gut were investigated. The data obtained in ~ormal subjects showed that HIDA provided superior hepatic duct images and rapid gallbladder visualization. Both agents showed rapid blood clearance. However, other differences were demonstrated which will be discussed. Thyroid hormones have a marked effect on cholesterol metabolism. They have been proved efficient in lowering plasma lipid concentration. The LDL clearance is increased from the plasma whereas the LDE synthesis is unchanged. However, D-thyroxine treatment induces high levels of plasma bilirubin concentration and increased activities of serum glutamic oxaloacetic transaminase and alkaline phospbatase. To investigate sensibility of the hepatobiliary radiopharmaceutical 99mTc-diethyl IDA to small changes in liver physiology, we have studied the influence of a short-term pretreatment with thyroxine on hepatic uptake and excretion of the radioactive agent. These biodistribution studies were performed in mice after the following treatment: control animals in group (I) were injected s.c. with saline only, whereas the group (II) received s.c. thyroxine at a dose of 3 ug/20 g b,wt. per day for 9 days, 99mTcldiethy] IDA was injected i.v, 2-3 hr after the last dose of thyroxine and the animals were sacrificed at various time intervals until one hour after injection of the radiopharmaceutical. The results snowed that the one-hour excretion of 9gmTc-diethyl IDA into intestine was significantly decreased (68.9% to 27,2%), whereas the excretion into urine was significantly increased (10.2% to 42.2%) after treatment, Thus, alterations of kidney and intestinal excretion of ggmTc-diethyl IDA are an early effect of changes induced by thyroxine treatment in mice. Laboratory ef Radiopharmacology, Isotope Dept., N.R.C. Demekritos, 153 41 Aghia Paraskevi,Attiki, and Therapeutic Clinic, IKA, Athens, Greece. The anion exchange resin cholestyramine has the ability to chelate with bile salts in the intestine, thus eliminating them in the feces. The entero-hepatic circulation is broken, serum bile acid levels fall and serum cholesterol drops. The serum bilirubin level tends to fall. Cholestyramine increases fecal fat even in normal subjects. To study the effect of such kind of changes, related to bile salts, on the processus of 99m-Tc diethyl IDA-hepatobiliary excretion, we have performed biodistribution studies of the above radiopharmaceutical in mice after treatment by Cholestyramine~ The drug was administered by addition of 4 g of resin to 150 ml of drinking water. The ingestion of that mixture by the animals lasted 5 days before the injection of gge-Tc diethyl IDA. The biodiatribution study showed normal blood clearance and hepatic uptake of 99m-Tc diethyl IDA. A significantly higher than normal level of radioactivity was found in the gallbladder from the 5th min to the first hour after iRjection (14.3% to 4.2% at 1 hr), and the excretion of radioactivity into intestine was lower than normal (50.1% to 68.6% at I hr). It is suggested that conditions similar to cholestasis are simulated in mice by cholestyramine treatment. That effect may be related to the resininduced disruption of the enterohepatic circulation of bile acids. Restrained elimination of radioactivity from the gallbladder into intestine would be the consequence of these induced changes. Laboratory of Radiopharmacology, Isotope Dept., N.R.C. Demokrito5, Aghia Paraakevi, Attiki, Therapeutic Clinic IKA, Athens, Greece. The value of IDA-ecintigraphy in the diagnosis of cholecystitis and other bil].iary channel abnormalities has been well established. But currently available procedures require fol]ow-up of fasting patient for 4 hrs or even more in the event of non-~isualisation of gallbladder. This causes inconvenience not only to the patient but e.lso dlffleulty in the routine functioning of the nuclear medicine department. We have studied the pattern of billiary dynamics in the CBD and tried to distinguish chronic from acute choleoystic. This presentation is based on Te-g9m-~IIDA study of 40 patients in which diagnosis was established byelinical~ biechemical~ ERCP or operative findings. After I.V. injection of 4 to ~ mCi of Te-99m-EEIDA data collection was done at 30 see per frame upto 45 min. Late pictures were taken when required. Reigion of interest was marked over CBD and time activity curves were drawn. ~ollowing observations were made: a) i£ T-max of CBD curve is IOz 2 min the gallbladder is vlsualised early in most cases b) If T-max of CBD curve is 12-I~ min and half time of fall is 13~ 3 mln then g~llbladder is not visualised in late pictures as in acute cholecystltis c) If T-max of CBD curve is 18-26 min and half time of fall Is greater than~O mln then gA1]bladder is visu~lised in late pictures as generm:iSy h~ppens in chronic eholecystitis. The present study shows that by analysing CBD cu~es~ it is possible to predict the gallbladder visualisation so that patients need not be kept fasting for long hrs. Portal-systemic shunting is an important consequence of all diseases that lead portal hypePten s~on. A practical and noninveslve technique to evaluate hepato-fusa] f~ow by recta] infusion o£ a radiotracer is described. The basis o£ the test is to profit by the presence of the inferlor po~ taceva] anastomosis, that, trough the inferior mesenterlc vein, connects the splenic vein to the recta[ and anal network, in order to ~emonstPate the shunt. Fast{rig subjects ~re placed in She supine posit~on and 3mCI of mgc0-were infused by a mlCrOclysteP (~ml). A computerlzed large field sclnt~l[ation camera with a 140 keV parallel hole collimator was positioned to view the entire liver and heart from the anterior aspect, Images with e 64x 64 resolution were recorded at the rate of one per 20 sec for 5 min. Were obtei ned the histograms (activlty/t~me) of two regbns of interest (heart-H, liver-L) a~ter the test a,~ the ratio H/L was calculated. In the normal subi ects, morphological findings were the immediate visuailzation o~ the liver end subsequently o£ the heart. H/L ratio at 2 min was • 0.5, ~n 32 clrPhotJc patients with portal hypertension (ego phages] varJces and hJ9h wedged hepatic vein pr~ sure-WHVP) the tracer reached immediat[y the heart and the H/L ratio was constantly > 1.5. A close correlation was found between the H/L ra tic and WHVP, concentration of serum albumin and pPotrombin time. This technique is shown to be useful in assassin 9 and in monitoring the patients wlth portal hypertension, After inhalation (Veenstra XV~133) or intravenous application of 133-Xe the course of activity was registered with an Anger-camera (Picker Dyna 4) over the upper abdomen (liver and spleen) as well as the exspirated air and recorded and stored by a computer (DEC PDP 11/34) Measurement of hepatic blood flow was performed in 19 patients with cirrhosis of the liver and we found a flow of 55.8+11 ml/100 g~/min. In five patients we ~d this investigation twice on the same day and with one hour interval and there was no statistical difference between this two measurements and we found a very good correlation (r=O.976). This noninvasive technique for measurement of liver blood flow is easily, rapidly and repeatedly performed The results suggest that liver blood flow is decreased in patients with liver cirrhosis as we could show in former more invasive investigations with 133-Xe. With the splenoportography(direct injection of 133-Xe into the spleen) we found in patients without liver disease a flow of 103.4+12 and with cirrhosis of the liver 0f--58.1+12 ml/lOO gm/min. Simultaneously this ~echnique provides a good information of the presence of extra-and intrahepatic shunts. With the arterial method (133-Xe into the A. hepatica propria) we found the liver blood flow with 89.9+3 in patients without liver disease and of 49.3+11 ml/ 1OO ~/min in patients with cirrhosis of the liver. The retrograde-venous method (133-Xe into the hepatic vein) showed in patients with liver cirrhosis a flow of 50.3+11 ml/100 gm/min. Radiocolloid kinetics within the first two minutes after i.v. injection is described with a new model which takes into account vascular transport thr E ugh dual hepatic circulation and extraction by Kupffer cells. 99mTc-human serum albumin colloids (3-4 mCi, 2-20 nm particle size) were used~ Images (32x32) were collected at the rate of one per second using a large-field-of-view computer i zed gamma-camera. Curves obtaimed in several ROIS were analyzed automatically and parameters of the model were evaluated by means of a non-linear least-square procedure: extraction efficiency (E); transit time (T), arterial flow (AF) and venous flow (VF) through "functional" hepatic paren~n~a; transit time through intra-hepatio artero-venous anastomoses (TS) and shunted arterial flow (SAF); and hepatic clearance (CI=E(AF+VF)). Freliminary results (Table) are in agreement with well known physiopathological data. The method proposed a£ pears to be simple, fast, safe and reproducible, and thus suitable for routine use in the assess ment of liver hemodynemics for clinical purposes. Possible applications include the follow-up of phs]~macological and surgical treatment and the differentiation between arterialized and non-art E #ialized liver lesions. After an injection of 99mTc04-liver perfusion examinations were carried out, then the TFS were computed by a program package /UNIDEK/ of the gamma camera computer system. On the basis of liver TPs /L-TP/ a new method to analyse quantitative liver perfusiou examinations was found out° L-TF gives the arterial mean transit time /MTTa/, the portal MTT ~TTn/, the ratio of arterial and portal blood flow / A/P / and the shape of the portal upstream. The computed L-TFs are independent from the quantity of the activity injected and from the efficiency of detection, thus data of different patients can be compared quantitatively. Normal values /14 control patients/: MTT~=5.is SD~l.3s; MTTp=20°4a SDi5.3s; A/~=19%/81% SD±8% . Pstzents with portal hypertension /ll cases/ : MTTa=6.3s SDil.4a; MTTo=IO.Ys SDi4.4s; A/P=53%/47% SD!15% • MTTp is significantly shorter /p 7) and it is also impossible to distinguish GERs of bile mixed with acid juice. To study these kinds of GERs we me dified the seintigraphie technique used for detecting duodenogastric bile reflux In a series of 5 patients who underwent partial gastric resection (3 Billroth II and 2 Billreth I) with moderate-severe esophagitis and without significant pH metric test variations,we administered i.v. 5 mCi(185 MBq)of 99mTc-HIDA,the pa tient lying under a computer-assisted gamma camera.When gallbladder image was evident(15-45 min after injection),Caert ! lein was infused i.v. at a dose of 2 ng/ kg/min for 15 min to induce gallbladder contraction.During the subsequent 45 min the patient was asked to perform a sta_n dard series of manoeuvres to facilitate GER.Time/activity curves obtained from areas of interest corresponding to stria remnant and distal esophagus she wed that in each patient at least one of these manoeuvres was followed by a peak in the esophageal curve,indicating a 99 mTe-HIDA-tagged bile GER. In conclusion, as this test gave positive results in pa tients in whom esophageal pHmetry failed diagnostic aim,we believe that HIDA-GER dynamic seintigraphy may be useful in d l secreting the biliary origin of an es~ phagitis. The egg meal for gastric emptying studies is generally labelled by 9g-m-To radiopharmaceutical$ Aim of this paper is to introduce a method for labelling the egg white by lll-In.400 uCi of i!I In-oxine in 50 ml saline has been mixed whit 3ml of fresh egg white.A second dose of 200 uCi of lll-ln-oxine was injected trougththe egg shell by a 23 gauge needle, without crashing the yolk. The sa~e tecnique was ergployed to mix 99-~n-Te sulfur colloid, 99-m-To mierospheres and 99-m-To ovalbumin to the egg.20 minutes later the mixture was tested by G 25 sephadex column chromategraphy and by 9% glycine gel eleetrophoresis,pr~ viously set by fibrinogen, human serum albumin (HSA) and ovoalbu~Jn (OA).Dhl~omatography and ale ctrophoresis indicated that more than 96% of the radioactivity is bound to high weight proteins having eleetrophoretie motility close to that of fibrinogen;S.7% is bound to lighter proteins wi~h an eleotrophoretic motility near to HSA and 0A; finally the 0.16% is due to free lll-ln.The ant! re eggs were cooked and sliced.Slices were imaged by a ganrna-camera.Images of the egg slices demostrated an homogeneous tag of the egg white and no actfvity in the yolk,whereas images of sl~ cos of eggs tagged by 99-~-Tc r~diopharmaeeu~cals showed a strongly unhomogeneous distribution of the 99-m-Tc inside the egg.The results suggest that the ill-In tags the egg white proteins,providing an easy to perform solid meal marker. It has been obtained an homogeneous and high yeld label. gha.i.r ef Nuclear Medicine, Institute of Radiology, University "Ls Sapienza", 00161 Rome, Italy We have studied the gastric emptying in 12 patients(mean age 35 and range 26-60 years)after Nissen fundoplication repair of sliding hiatus hernia and 13 normal subjects(mean age 32 and range 27-40) after ingesting a solid meal(two scrambled eggs labelled with 1 mCi of 99mTc-SC). In the first group of 12 patients the study was performed in basal conditions and repeated one week later after intravenous injection o£ i0 mg of Domperidone immediately after meal @dmnistrarich. The data collections were carried out by large field gamma-camera (SELO GANMA-CAT) on line wdth Digital Computer PDP-II; 60 seconds frames everg 15 minutes for 3 hours, using a 64x64 maatrix in word mode. The T i/2 and the percentage values in the various times were estimated on the total gastric area after flecay correction. The T i/2 in the healthy patient~ was 90 minutes ± 8(SD) with range 45-125. The T 1/2 in 12 patients was 130 ~ IO(SD)(p O01) Only 8 patients who had a delayed T 1/2 showed a significant reduction of this parameter after Domperidone. On the other hand no significant variations ~ere seen in the 4 patients with normal T i/E. Several radiopharm~ceutical isotopes have been introduced for measuring gastric emptying rates. Tc 99 m sulfur colloid incorporated in small R pieces of filter paper and coated with Perspex has been acted as a marker of solid component in the meal. Kolestyramine is an anion exchanging polysterin resin, the ability of which to bind Tc pertechnetate has not been tested earlier. We studied the stability of Tc-Fiperspex and Tc-Kolestyr in gastric juice of two different ph (below two and above six) in vitro at 37C for three hours. Tc-Fi-Perspex was prepared by impregnating the filter paper (3 mm x 30 ms) with a total of 200 uc of Tc 99m sulfur colloid, a minimum of which was in noneolloid form. After drying the paper was dipped in a 3 ~ w/v solution of Perspex in chloroform, dried, redipped and dried again. The filter paper was then cut imto 30 pieces (I mm x 3 mm) Tc-Kolestyr. was prepared• by mixing I g kolestyramlne (Questran) in 15 ml aqua with 250 uc Tc pertechnetate for ten minutes. During the inkubations, Tc-Fi-Perspex released radioactivity 20 ~ when ph in gastric juice was below two and 5~when ph was above six. Tc-Kolestyr released radioactivity 0.7 ~ and 0.5 ~ respectively. Our results show that a great amount of radioactivity is eluated from Tc-Fi-Perspex in gastric juice. Te-Kolestyr, however, remained stable in gastric juice the stability being over 99 ~-The similar good ability of other polysterin resins to bind technetium has been also noted in earlier tests. Tc-Kolestyr, easily prepared radionuclide complex, appears to be suitable for a semisolid marker of a meal in gastric emptying studies. An essential step for deciding supra selective vagotomy and controlling its efficacy, or for diagnosing unfrequent gollinger-Ellison syndrome is the estimation of basal and stimulated acid output. This is classically performed through gastric aspiration before and during continuous perfusion of Pentagastrin (6 ugr/Kg B.W./hr). 9~nTc Pertechnetate is taken up by the gastric mucosa either by parietal cells or mucus cells but controversial results have been published. It has been proposed as an alternative method for estimating acid secretion. The present paper describes an original method for calculating gastric Pertechaetate clearance by simultaneous measurements of gastric uptake and plasma concentration with a scintillation camera connected with an all purpose mini computer with visually controlled ROI selection. In all cases studied, the gastric equivalent plasma space shows the same typical time evolution and the clearance may be easily calculated from its initial rate of change. In preliminary studies, classification into normal and duodenal ulcer patients was based on endoscopic examination. Gastric Pertechnetate clearance was significantly higher in duodenal ulcer patients (62,4 ml/min + 27 vs. 27,9ml/min ! 9,6 in normals). Incrnased clearance is observed after Pentagastrin stimulation, while decreased clearance is observed with Cimetidine. Our results suggest a similar trend for gastric aspiration results and Pertechnetate clearance values. If further studies demonstrate an adequate correlation between these two parameters, our simple and non aggressive method would advantageously replace a time cons~uing and uncomfortable e.vploration. The purpose of the study was to estimate the normal values and to compare them with those of patients with sirra syndrome. Computer-based sciotigpaphy was pepfo~ed in frontal view. 75 MBq of 99mTc-pe~technetate was injected i.v. and 10 min later 0.25 mg of carbacholchloride s.c. to stimulate salivary flow. The total examination time was 30 min, Tlme activity cuPves were obtained over parotid and submandibular glands and over a skull region. Maximum/background and maximum~minimum Patios were calculated. The study was carried out in 64 healthy people with no evidence of salivary gland disorders. The results were analysed with respect to age, sex, smoking habits and history of virus parotitis. 37 patients with sirra syndrome served as a comparative population. In the normal population the findings were very s~rmetcical. There were no differences between males and females, smokens o~ non-smokers, people with o~ ~ithouf history of parotitis. A slight decreasing function was found in elderly people. All patients with sicea syndrome had an abnormal finding which correlated to the severity of the disease. No significant side effects were observed. The method is of value, wbeo disturbaoce in the function of salivary glands is suspected. This method shows a clear difference in findings between the healthy people and patients with sirra syndrome. It is possible to estimate the degree of the functional distucbance, observe the pnog#ess of the disease and estimate the efficiency of the therapy. Tampere University Central Hospital, SF-33520 Tarnpere 52, Finland A right subphrenic abscess may Pe detected on a radionuclide lung-liver study by a separation of pulmonary and hepatic activity, since the liver lies close to the diaphragm and thus to the l,~ug. We have studied 65 liver-lung radionaclide scm~s using respectively Tc-99m-colloid and Te-99m-MAA. The study concerned 3 ~oups of patients. The seintigraphic results have been compared to the su~-gical abdemtual exploration in the first group, to the combined results of abdom/~al ultrasound and C'f scan in the second group, and to the considered final dia~osis assessed by clinical examlretion, radiologica! and biological investigations and the evoluzion in the third group. The images were interpreted as positive when there was separation between liver and lung activity in anteriorandri~ht lateral views and when the upper part of the right lobe was normal on Tc-99m-eolloid imaging. Chest x-ray was available in 61 patients; it has been useful to confi~ the presence of lesions in the right pulmonary base. Among the 28 patients of the first group, 22 ~md normal radionuclide scan and no subdiapl~rag~atic abscess, 4 had subdiaphragmatic abscess also evidenced by the scintigraphy. One patient had a positive scan and an hydatic cyst at the liver dome with a fistula through the diaphra~. In the last patient has been found a massive subcapsular hematoma of liver with rupture. The scintigraphy was negative. In the second group of 12 patients, li had negative scan and no subphrenlc collection showed by ultrasound and CT scan. In one patient who had pneumonia in the lower part of the right lung, the scan was falsely positive. In the ~hird group of 25 patients, 24 had negative scan and no subdiap~u~agm~tic abscess. In the last patient who bad surinfeeted right pleural fluid, the scan was falsely positive. Despite the relative weak prevalence, these results confirm the usefulness of the radionuelide scan for the detection of right subphrenic abscess. Rout~e chest and abdominal x-ray films should be available when evaluating liver-lung scan images. Gastroesophageal reflux in children has been implicated in various respiratory recurring diseases. Several techniques including oesophageal pH testing and scin tigraphy have been devised to detect and quantitate gastroesophageal reflux. Limitations have been shown for each test : short duration with gamma-camera or restricted acceptability of pH probe by children. A radionuclide screening test for gastro esophageal reflux suitabie to children has been developed. Single INs (T1) probe eollimabed with lateral window ~s in CONTACT with sternum. Thzs probe is connect to a single channel analyzer and microcomputer for data storage. A oral dose of TO MBq of 99mTc phytate (Sn) followed by apple juice are given. Measurement or oesophageal radioactivity is continued for i hour by lO seconds sequences with real time display of acti vity. First 50 results are analyzed. To vali date this mebhod, on 5 patients we simul taneous record g~stroesophageal radioactl vity with single probe and with gamma camera, For conclusion, easy to use, well accepted by children, without immobilizing large equipment, this new method seems to be usefull for screening reflux in pediatric estate. Department of 8iophysic and Nuelesr Mede ripe. H6pital Tenon 75020 PARIS FRANCE. OF DYNastIC ~CIN21-GRAPIg/ OF KIDNEYS IN CHILDREN. K. Teth, Ms Wr~bl~w~ka, L. Skobejke, E. Cichocka ~d No Ko~ieczny 380 ex~linatie~e sf kidney~ in patients frem 2 w. t~ 18 y. h~v~ been dens. Du-riHg the~s exams 99m2c-DTPA was injected as bolus and the frmmes were being raglotered during 30 min. /~aring first minute 2 seconds'frames, th~ i0 seconds" omss/~ Durimg the 2~d and the 3rd minute the relative GFR far bsth kid/aeym was caleu/~ted. ~he ten,graphic curv~ ~ere ~v&luated by classic semi-quantitative methods amd the medium transit time fer each whsle kidzey was calculated by decomvelutisn a~lysie. Im cases of serious disturhamees sf @utflew fure~emide was Injected. The f@llewi~reeults h~ve ~ee~ ameer-~aimed as the meet useful ames for the clinleal purposes: relativ~ GFR ia qUa-lifieatie~ far evem%u~l me~hreete~k7 , furssemlde exam effect in ~aae~ @f @~etrusted er me~-ebstructed dilatatie=a, e~rly 9e~t--sperative exam~, ev~luatism ef imvisihla ~r peerlyvieible kidneye imurs.graphy ~md fumetio~l evaluatiem ef set,pie kidmeya, The Mem@rlal H~ital, Ohild Health Centre, AI. Dmieel P~lekieh 20, 04-736 W&rszawm, Psl~d Renal size in children has been studied radiographically and by ultrasound. Radioisotopic methods of measurement are scanh in the literature. Diseased kidneys frequent/y fall outside the normal range of size and thus demonstration of abnormally large or small kidneys is of value. 282 scans frcm 259 children, mean age 5.65 years (range 20 days to 14 years) were studied who had had either a DMSA scan or a DTPA renogram or both in the previous 14 mths. 155 had a DM~A scan, 72 had a DTPA renogra~, 16 had a DMSA scan and a DTPA renograrn, 10 had 2 DTPA scans and I also a DY~A scan and 6 had 2 DMSA scans. ~OIs were r~e round the kidneys by hand in the 128x128 images and with the help of a gradient image in the 64x64 knages, and the area of each kidney and its maxim~n length was calculated. Studies in which the patient had moved were rejected. The 2 minute rencgr~ image was used as being representative of the renal parenchyma without pelvic contribution. TO calibrate the size of the TV image we used a phan-tc~n of nine accurately spaced point sources, 2 magnifications of the image and 2 ~atrix sizes for aquisition. The size of the kidneys for the Di~A and the DMSA images was compared both together and separately with the radiographic size and the DMSA images were compared with the DTPA images. The results are discussed. Radioisotopic studies can be used to provide valid measuren~nts of kidney size under suitable conditions and are especially useful for follow up studies in petie~hs with various renal disorders. Division of Nuclear Medicine. Department of Cli-Dical Therapeutics, Athens university, "Alexandra" Hospital. Vassilissis Sophias Ave. and K. Lourou sir. 115 28 Athens, GREECE. In our institution a direct radionuclide method for the investigation of vesicoureteral reflux has been in use for the last 8 years. In the method cathetherization of the child is done immediately prior to instillation of 0.9 % saline with Na99mTc04 added. Instillation is continued until voiding urge is reached. D~ring instillation and voiding computerized images of 5 seconds duration are continually obtained. Total investigation time is usually 5-10 minutes. Reflux to the kidney pelvis is reliably demonstrated. Generating time/activity curves for the reflux and evaluating the degree of reflux, it is possible to divide the patients into three groups: One hundred and sixty-nine children suspected of having malignant disease were examined by 67-Gallium scintigraphy. In 99 children with untreated diseases at the time of examination, abnormal accumulation of 67-Ga was found in 51 patients, including 40 with malignant tumor. Forty-tree negative results were obtained in children with benign disorders. Five false negative results were obtained in patients with neuroblastoma of the adrenal gland. In 70 children with malignant diseases treated before the examination, abnormal accumulation of 67-Ga was seen in 40 patients, including 11 still suffering from malignant disease. The results of 67-Ga scintigraphy in all of the children were evaluated qualitatively. For the final diagnosis of malignant disease, diagnostic specificity was 86% and diagnostic sensitivity 79%. The prevalence of malignant disease was 56%. It is concluded, that 67-Ga scintigraphy should he used for primary visualization and control of malignant tumors in children. Department Q~ Nuclear Medici~e~ Rigs~ hospitalet,Copenhagen, Denmark. were pressed from the serum samples after addition of yttrium as an internal standard, mixing and evaporating at 30 ° with reduced pressure. The proton beam of the 2.5 MV Van de graaff accelerator ( University of Helsinki) w~s brought into the air through a Kapton ~ foil supported on a perforated carbon disc with about 200 exit holes, 0.3 mm in diameter. The samples were positioned at 45 ° to the incident h~am and the X-rays, due to refilling of the K-and L-shell~, detected with a Ge(Li) detector at 80 ~ to the beam. The current was typically 0.3 ~A and run tines S -10 min. The X-ray spectra were analyzed by the VIPUNEN program and checked manuallD Early pregnancy Se (0.045ppm) was higher than late (0.028 ppm, p<0.001) but cord levels lower than both these (0.016 ppm, p<0.001), findings in harmony with the incidence pattern of Keshan cardiomyopathy. Cord and maternal Pb were simila~ Cu, Zn, Fe and Ca showed known patterns. Maternal Fe was higher in intra-uterine growth retardation (1.7 ppm), Br in 9reeclampsia (3.59 ppm) and twins (3.61ppm) than in normals (p 55%, and 23 had cardiac catheterization. LV time activity curve was replaced by weighted sum of 7 Fourier garmoolcs, expanded to 512 points. The duration of diastole was normalized to heart rate. Filling rates normalized and expressed as % stroke volume/see. Parameters (PAR): (A) Peak Filling Rate; (g) Duration from nadir of curve to (A); (C) Average Early Filling rate within early diastolic interval corresponding to duration of i/4 of normalized diastole; (D) same as (C) but using duration of I/5; (E) 24 patients with documented coronary anatomy were studied by first pass radionuolide angiography using gold-195m (ti/2 30.5 see). 7 patients had normal coronaries (Nls)~ 5 had I vessel disease (IVD), 5 hsd 2 vessel disease (2VD) and 7 had 3 vessel disease (3VD). Ejection fraction was measured at rest (R) and at 3 mins (3')) 6 mins (6'), peak (P), i~m~ediate post (Ip) and 2 mins post (2'p) exercise. 5/7 Nls~ 2/5 IVD~ 3/5 2VD and 2/7 399 completed 6 mins or more exercise. In Nls ejection fraction was signifieantly elevated post exercise vs rest. In I and 2VD ejeetlon fraction was not signifieantly depressed at 3 and 6 mins but fell at peak exercise and rose i~mediately post and mins post exercise. In 3VDejeetion Traction fell at 3 mi~s and at peak exereise~ and rezained depressed immediately post exercise. At 2 min post exercise, in contrast to I and 2FD 7 ejection fraction was not significantly above rest. EF End diastolic and end systolic blood pool images were acquired tomographically using an ICE h00A rotating gamma camera and Star computer, and slices were reconstructed orthogonal to the long axis of the heart. Left ventricular volume was determined by summing the areas of the slices, and wall motion by comparison of end diastolic and end systollc contours. In phantom experiments this provided an accurate measurement of volume over the range 40nfl to 5OOml (r = 0.99). In h0 subjects who were either nor~l or who had coronary artery disease, left ventricular volume (r = 0.83) and left ventricular ejection fraction (r = 0.89) correlated well with those using a counts based planar technique. In g2 of 24 subjects who underwent right anterior oblique X-ray contrast ventrieulography, tomographic wall motion agreed for anterior~ apical, and inferior walls, but abnormal septal motion which was not apparent by contrast ventrioulography, was seen in 13 subjects tomographically. All 13 had disease of the left anterior descending coronary artery supplying the septum. ECG-gated blood pool tomography can thus determine left ventricular volume and ejection fraction accurately, and provides a global description of wall motion in a way that is not possible from any single planar i~ge. Scintigraphy beind a bi-dimensional projection of a tri-dimensionsl activity distribution, the activity detected in each pixel is the sum of activities from several overlap-p±ng or adjacent cardiac structures. Factor Analysis of Dynamic Structures (FADS) solves, automatically,the problem of crosstalk. It provides Factors which are estimates of the underlying physiological components and factor images which are estimates of the factors spatial distribution, this method was introduced by Bazin, Di Paola (1975) and Barber (1980) and used successfully in the field of dynamic studies. 47 consecutive RNA were processed using FADS. 13 patients were normal,18 had a congestive cardiomyopathy,5 a myocardial infarction, 4 a valvular disease, 2 an obstructive cardiomyopathy and 5 a shunt (3 left-t0-right, 2 right-toleft). RNA was performed at a 64x6A frame rate of 0.5 s. during I minute, after IV injection of 7 MBq/kg of 99mTcRBC. 5 factors ~ere obtained in anterior view, which corresponded to the superior vena cava (SVC), the right heart, the lungs, the left heart and a vascular factor including the recirculation. In LAO view, the fifth factor corresponded to the pulmonary artery. To focus the study on the right heart, FADS on the First frames provided 4 factors : the SVC, the right atria, the right ventricle and the lungs. The factors were unaffected by crosstalk and led to a non-ambiguous clinical interpretation. Results were computed to those obtained by the R0I method. The time to peak of each chamber was accurately determined by FADS. Particularly, the diagnosis of tricuspid insufficiency and shunts were easy to perform. Factors can directly be used to quantify the cardiac function. The method is automatic, has an exeelJent reproduelbility and is not operator dependent. This prospective study was performed to compare the value of 2 noninvasive diagnostic modalities Pd~V and 2DE in patients with acute myocardial infarction (MI) for both the primary localization, extent and hemodynamic consequences as well as for prognostic follow up. In 17 patients (mean age 55.2 yrs, range 38-72 yrs} with EOGdocumented MI BNV and 2DE were performed in an average of 5, ~8 and I05 days after the acute event. Both RNV and 2DE were scored visually by 2 experienced observers, blinded to the clinical and ECG findings, for location and extent of regional wall motion abnormaIities (RWMA), global ventricular function and the time course of these parameters. Results: In 7 patients with large infarcts (5 ant., i lot., t post.) primary location and the individual time course were recoqnized by both RNV and 2DE identically. In 4 patients (2 small ant., i intramural, t inf. MI) RWMA were seen with 2DE only, whereas in another 2 patienms only BNV succeded in detecting RWMA. In Z patients with intramural Mr, both R~V and 2DE slightly dislocated RWMA. In 2 patients with small inferior infarctions both methods failed. In addition ~o the target findings RNV revealed in 6 of 15 patients exercise induced RWMA, whereas 2 DE stud±as demonstrated a small pertcordial effusion in 4 patients, endocardial thro~g3i in 5 patients, and in i patient a papillary dysfunction could be verified. In conclusion, in large MI both RNV and 2DE are of almost equal diagnostic value, and it is this patient group that needs follow up studies for prognostic and therapeutic considerations. In smaller infarcts, however, both diagnostic modalities should rather be used complementary. We developed a computerized single cardiac-probe system combined with echocardiogram which permits the physician to position the probe more easily and properly. In this system left ventrieular ejection fraction(LVEF) can be estimated by the following three modes; first-pass(FP), beat-by-beat(B-B) and ECG multigated(MG) modes. In FP mode a complex demodulation technique is applied for estimation of background counts. The sensitivity of this system is high enough for FP and equilibrium studies with 1 mCi and 5 mCi of Tc-99m human serum albumin. In 40 patients with various heart diseases, the LVEFs estimated by the system using the abovementioned 3 modes were compared with those obtained by gamma camera. The correlation coefficients(r) between the LVEFs estimated by FP mode, B-B mode and MG mode, and those estimated by gamma camera were 0.938, 0.932 and 0.930 respectively. In 15 GEE is reliably detected by radionuclide studies. The presence of radioactivity over the lungs 8-15h after tracer ingestion suggests aspiration of gastric content. Usually these studies are performed with liquid tracers. Only about 10% of a liquid meal, however, remain in the stomach after 2h. Thus, the time interval in which GAB has to occur, in order to he detectable, is very short. Because about 40% of the solid label may be expected to zemain in the stomach after 2h, we introduced a combined liquld-solid labeled meal. 20 patients(ilM,7F)aged 23-aly(~56)were studied, i patient being studied twice. All pa tients presented recurrent respiratory disorders. The studies were performed in the late afternoon after 4h fast, the patient being supine. The esophageal transit of a single swallow of TC-99 m DTPA diluted in 10ml orange juice was evaluated for each segment with respect of transit times, motion disorders and GER. After dilution of the gastric content with 200ml non labeled orange juice a new dynamic study was started in order to visualize GEH. The third part of the investigation consisted in the search of GEE after a labeled solid meal(L egg labeled with Tc-99mDTPA before boiling). The next day, the thorax of the patient was imaged in order to detect pulmonary activity. 18/20 patients showed GEE after the liquid, 14 also after the liquid/solid meal, 18 patients presented motion disorders of the esophagus(prolonged transit time n=13, antiperistaltic n:18), BA was detected in 17 cases. The patient studied twice showed complete agreement between both studies. In i0 patients investigated with a liquid label only 4 cases presented BA. These data suggest a higher sensitivity for detection of BA of gastric contents with a tracer attached to a solid rather than a liquid meal. Nuclear Medicine Division and Medical Policlinic, Lausanne University, CH-i01t Lausanne The aim of this work was to compare the advanta gas and the Eimifafions of several data processing techniques for the assessment of esophageal transit. The following qualitative methodswere evaluated : (a) scintigraphic image (b) sequential images or cine-dispiay (c) regional time activity curves (d) a condensed image which consisted in replacing each image in the dynamic aerie by a single vertical fine, corresponding fo the projection of the image on the Y-axis. A condensed image was then reconstructed by puffing the Lines side-by-side according fo their frame number, The quantitative methods evaluated were the Fixer to pixet presentation of (a) curves parameters such as time of maximum etc. (b) mean transit time (c) ratio of first and zero moments (d) a time parameter calculated from the radioactive decay. Patients data consisted of Kr-81m esophageal transit study performed in 50 pafieots. The patient was placed with his back against the collimator and was asked fo swallow 10 ml of Kr-81m in 5% glucose solution. 60 one-second images were acquired and all the data processing methods described above were successively applied. The results showed that a qualitative method should always be used is conjunction with a quantitative method fo exclude causes of errors such as GE reflux occuring during swaLLowing or fo evaluate the spread of the input bolus. PixeL to pixeL prensenfafion of curves parameters failed fo separate normal and patho-Logical cases. The optimal method was the simultaneous use of condensed image and the pixeL to pixeL presentation of ratio of moments or mean time from decay. Since the dec~y of short-lived radionuclides occurs during their displacement in the human body, it is possible to calculate a transit time (TT) by measuring the decrease of radioactivity with distance : TT = [/k in At/A2, where A, and A 2 are the radioactive concentration in two points and ~ the decay constant. Experimental results were obtained with single bolus injections of 81mKr in solution. Demonstration has been made that TT is independant on shape of the bolus (short or long). TT is computed pixel by pixel and the radioactivity track is displayed in colors depending on the bolus displacement with time. From data observed on a phantom model, compared physical significance was made possible between commonly used terms such as arrival time, time to maximum, mean transit time. These studies were applied to different clinical routine investigations such as : -evaluation by means of intrahumeral injections, of a blood flow index in the finger tips after restauration of arterial trauma; -venography studies of revascularisation after venous occlusions. Variations of blood velocity can be estimated in the main or collateral pathways from saphenous vein to inferior vena eava; -oesophagial transit studies performed for the evaluation of oesophaqial disorders and postoperative follow-up. Specific merits of the single bolus method are discussed in respect with the constant perfusion method and in relation with the half-life of the injected radlonucliaeLs) and possible applications to SPECT. mo ±6 post-gastroplasty, patients ate a meal of one Scx~mbled e~ labeled with 0.5 mCi of Tc-99m SC and emptying of the stomach or pouch was quantitated usin~ a 8amma camera. The data were expressed as a fraction of maximum activity and a half-time (T½) of emptying calculated. Gastric emptying of the solid meal in normals was linear with a T½ of 13-59 minutes. Nineteen preoperative patients had normal gastric empty-in~, i was rapid, 1 very delayed, and 5 borderline delayed. Half the patients showed a latent period of emptyin~ or a delayed peak. In the 2-year postoperative group, 7 had good results (>60% excess weight loss), and 5 had satisfactory results (40% -60% loss). There was strong direct correlation between pouch size, T½ pouch emptying, and percent of excess weight loss. The S patients with enlarged pouches had the most dramatic weight loss. We conclude that the AGES appears eo be an extxemely valuahle test for menitorin8 gastroplasty patients and may provide clues to the physiology of weight reduction i~ these patients. Because of the high correlation between pouch T½ and weieht loss in successful postoperative patients, the most useful aspect of this test may be in differenti&ti~ the reasons for failure of weight loss, i.e., inadequate surgery [short T½) versus patient overeatin~ (normal or prolonged T½). There is no definite ~vidence that abnormalities of gastric emptying play a role in the etiology of excessive obesity. Esophageal functional scintigraphy (EFS) assessing both the esophageal transit and the gastroesophageal reflux proved to be a sensitive,quantitative and noninvasive screening test for esophagus dysfunction. However, since bolus composition has some effect on the emptying of the esophagus, the only use of liquids may be questionable. Therefore we tried to determine whether the transit rate of so]Jd food furnishes additional information about the fuectLonal state of the esophagus. Patients and methods: 70 consecutive patents referred for suspected esophageal dysfunction uederwent EFS after swaltowing f~rstly 15 ml of water m~xed with 5 MBq TC-99m-DTPA and then a two centimeter cube of identically labelled b~scuit. The results were expressed as 10 sec clearance (%) and transit time (sec) respectively. The reflux test was performed according to the method described by FISHER et at (Gastroenterology 70:301,1976) . Results: 30 % of the patients showed normal, 27 % patho-logica~ transit of both the liquid and the solid. 20 % bad a regular clearance of ]iqu~d but ae impaired evacuation of the solid bolus. The inverse was found in 23 % of the cases. The mean reflux index of the groups of patients w~th discrepant results was 6,0 + 2,6 % and 9,2 + 5,0 % respectively. When considering only patients without suspected or proven collagen disease, chronic duodenal ulcer was more frequent in the former group (7/9) and reflux disease w~th hiatal hernia in the latter (6/8 Panoreaticoduodenectomy with pylorus preservation (Lon54 ng/ml), although they had undetectable hTg values duping the hormonal replacement. This study shows that serum hTg, in patients with early thyroid cancer previously submitted to surgical thyroid ectomy, is often undetectable during th~ suppressive hormonal therapy, although the p~tients have ~esldual tissue in the thymold bed. Moreover, it shows that a group of patients, to all appearance homogeneous, could be divided in 3 subsets according to the variations of serum hTg levels during the suppressive therapy withdrawal. The thyreoglobulin (TG) concentration was measured in the sera of patients with differentiated thyroid carcinoma who had undergone surgical treatment, In a]most all of them radioiodine ablation of the thyroid remnant was done. TG was measured by commercial kit in the range of 20-1280 ng/ml, A total number of 133 patients were included in the study and some of them were monitored during a longer period of time. In the sera of 63 patients without signs of tumour tissue, undetectible or low levels were found. Somewhat higher level was found in 7 patients in this group (x=77.6±19.5), but these values were considerably lower than those measured in patients with metastases. Increased TG levels (~=723.5±491.3) were found in 20 patients with recurrence of metastases which do or do not accumulate 1311. Low level of TG was found only fn two patients with metastases without uptake of 1311. Determination of TG in the sera of patients with differentiated cancer is of importance in observing such patients, particularly if we could monitor TG level during a longer period of time. The serum eoneentrations of 4 tumour markers(TM):carciuoembryonic antigen(tEA), alphafetoprotein(AFp),beta~microglobulin (BgM) and ferritin(FF~) ha~ been deter-mi~ed by the radioimmunoassays in 60 patients with breast carcinoma~before the operation and other treatment.The patients were divided into: group A with localised carcinoma(28) and group B with carcinoma affecting the regional lymph nodes and/or producing distant metastases(32).No significant dependence was proved between these groups of patients and TM levels(p>0.05).The elevated CEA was found in the smell number of the pa-tiemts~more frequently in B than in A (18.8% versus 10.7%)~its concentrations in A were elevated only very slightly (from 15 to 261ug/1).B~M and FER were elevated in uea~ly the game percents in A and B(BvM:39.5% against 37.5%~FER: 42°9% agaTnst 46.5%).AFP was within the normel limits in all patients.ln the both groups the percent of the patients with elevated TM(67.9~ versus 59.4%) did not differentiate significantly(p>0.5), but in A were significantly more frequent the patients with elevated one TM (p iO ng/m/) also in ZO pts without meta stases nevertheless in all but one the value was lower than in the pts with metastases (iO to 30 ng/ml) and did not show any increase. Se rt~TPA level ranged from ISO to 13OOU/L in the pts with metastases while it was lower than 120 in all the other pts but 3. In these 3 pts sert~TPA was 140, 146 and 320 U/L respectively; the last had chronic hepatitits and the other two showed signs of liver disease. No increase of these values was observed. These data show that false positive results produced by ser~a CFA and T?A determinations are lower ~Id more easily identified than those produced by BE. The refore these tomoral markers are suitable indi cators of distant metastases while BS can be successively used to localize metastases. 167 female patients (average age 55 y) entered in this study, among them 29 clinical stage I, 81 stage II, 55 stage III and 2 without preci-sion~ 64 premenopausic and g9 oostmenopeusic. The serum CEA level has been determined by radioimmuno-assay using a commercial kit, during the first week of the postoperative X-ray treatment and at least 3 times during a 18 month follow-up period. 113 among these patients undervent a posteperative combined internal mammary (IM) and sxillary lym0hoscintigraphy. (LSC). As shown by these 167 patients,an initial serum tEA value superior to 5 ng/ml constitutes an independent pejorative prognostic factor in comparison to the following individually analyzed indices : tumor size, clinical and postoperative histological axillary nodal status, estrogen receptors end menopausic status.lf serum CEA-level and internal mammary LSC are combined,oatients with higher than 5 ng/ml as initial value and positive IMLSC present the highest recurrency rate after 18 months, whereas in patients with low CEA-level (~5 ng/ml) and normal IMLSC there was only 4 recurrencies out of 42 cases.The combinaison of both (initial serum tea-level and IMLSC) prognostic factors studied is able to modify even the contribution of postoperative axillary nodal status as established by anat.-path. examination. As far as the follow-up period is concerned : in 82,3% of the cases the evolution of the serum tEA-level corresponded to the clinical course. Among the true positive cases (rising CEA-level corresponding to a proven clinical recurrency) in 21,8 % of these patients the modified CEA value was the first sign of this evolution. Laboratoire des Radio-lsotopes, Institut Jules Bordet, Universit6 libre de Bruxelles, 1000 -Bruxelles, Belgium. Cancer of the breast is the most common malignancy in fenmles affecting approximately 7% of all women. X Ray mammography will detect 90% of all breast cmlcers but has 3 distinct problems: i) Unacceptable levels of ionizing radiation, 2) Difficulty in defining breast parenchymal pattern, and 3] High false negative rate. To evaluate the ability of magnetic resonance imaging to outline the anatomy of the breast using different pulse sequences. Twenty female volunteers who undem#ent mm1~nography with no evidence of breast cancer were studied. All patients were studied using a prototype breast solenoidal coil 6.5 cm deep and 16 cm in diameter. Patients were examined in the prone position and the total length of examination depended on the pulse sequence. Thirty-two thin sliced magnified images were obtained on each breast in approximately l0 minutes. Results : l) Magnetic resonance imaging is very acceptable to the patients with no known hazard, 2) The anatomical details are superior to xeromanmlography, and 5] The slice magnified tech nique affords excellent spatial resolution. In comparison with former methods the new assays needed only half the quantity of tumour tissue and distinctly less time for the measurement of radioactivity. The concentration of both astradiol and progesterone receptors was raised in 24 turnout cytosols indicating that hormonal therapy may be recommended i n these women. An increased level of solely estradiol receptors was noted in 9 tumour cytosols and of only progesterone receptors in 2. The concentration of both estradlol and progesterone receptors wasbelow20frnole,/rrg cytosol protein in 21 tumour cytosols. In conclusion, for mammary tumour cytosol an improved estrogen and progesterone receptor assay wlth 1-125 estradlol and a H-3 labelled progesterone dedvatlveas ligands is highly practicable, especially by saving time and by requiring only small tissue samples. This wag ten patients underwent 24 peritoneal scans prior to the administration of a chemotherapeutic agent, mitomycin C, for intraperitoneal spread Rrom sn ovarian m~lignancy. None of the patients had koown pulmonary oR bone mGtastases. All patients had multiple laparotomies and laperoseopies and one patient had local abdominal radiotherapy. The adhesions that had developed as a result oE the above, were the cause of incorrect catheter placement in Eour patients as well as a suboptimal distri bution in most scans. In two patients activity was seen within the large bowel, in ane patient in the small bowel. Tn one patient the catheter appeared to ly in the lesser sac. We ~eel that the To-gBm-HSA peritoneography is a simple but indispensable methad in establishing the catheter position as well as studying the expected distribution of the ehemo- Aims of our study were detsrmioation of TPA and CEA in pa-ti~ wit% lung cancel,and evaluation of ~neir clinical usefulness in monitorin~ cancer treatrent. We have studied 65 patients with ic~ cancer (30 squs~ous cell carc~,8 8denocemc~ncmes,5 oat cell care/nones, 4 la~e cell c~rcincmas,snd 18 IL~ cancers with indef~z/te histslo~.Ten patients withcut mah~nant disease ca-st{Luted the control ~roup. lh~ive patients out of B5 were mc~itored durin~ ~ncer treatment. I/l the ~rot~o of cancer patients the mean value of CEA was 11.63 +-19.2 (~), while in the control ~roup it was 3.17 ~ 5.2 (~) (p¢0.oi). ~errs3re the mea~ value of TPA was 128.54 +-75.11 (SD) in the group of cancer patients,whiie it was 87.42 ± g5.32 (~D) in the control group (~O.Ol).TPA and CEA d/drRt show any si~nificative correlation, When we considered the histhlo~ we ~oted a mean value of ~A .Dre increased in aderloc~'cinc~ (23,75 +-19,9) Thelreatment o[ patients with carcinoma of the bronchus has been improved markedly during the last decade. This progress was partly due to the determination of turnout markers in the serum of these patients which provided informetlon about growth, metastasizatlon or, alter therapy, recurrence of the turnout. We investigated the frequency of elevated serum levels of several tumour markers including those which had been ~ntroduced recently. Thlrty-six patients (27 men and 9 women) aged 24 to 80 years were examined who suffered from carcinoma of the bronchus of different stages. In 5 patients metastases been found. At the time of study, the carcinoma of the bronchus had been removed surgically in 12 patients whereas the other patients who could not undergo surgery received chemotherapy. The serum concentration of TPA (tissue polypeptide ontlgen), ferritln, g~-mlcrogIobuUn, CEA (carc~,oembryonlc antigen), "CA 12-5, CA 19-9, AFP (0~l-fetoprotein), 6-HCG, and ACTH was me~ured by radioimmunoassay. Showing different patterns in serum, TPA was raised in 23 patients, C£A in 21, [errlt{n in 20, 62-mlcroglobulln in 9, ACTH in 8, CA 12-5 in 7, 8-HUG in 2, CA 19-9 in one patient, and AFP in none. In view of these results, TPA, CEA, {err{tln, 62-relateglobulin, ACI"H, and CA 12-5 were the most rewarding turnout markers. In these patients a strong relatior~ship was not evldent between the patterns of increased levels of tumour markers in serum and the stage o[ the disease. In conclusion, radioimmunoassay of several relevant tumour markers in the serum of patients with carcinoma of" the bronchus appears to he valuable for early recognltlon of tumour growth, recurrence, or metastases. is th&t between epidermoid~l smd non-~ifferentiated carcinomas, in which the values are significantly different. The adenocarclnama s~nd the epideraoidal groups were further divided according to the index of cellular deviation end the respectively assigned 0EA and ~PA values in the various sub-group@ were compared. AS regards the mean values, pa~hieularly in relation to the TPA ther~ is a significant increase in the values passing from G I to G . The statistical significance in the ~arious comparisons deem high for the TPA particularly in the G and C comparison in the ~pidezmoidals (p< 01005) , 5 aund the G and G 2 in the adenocarclnomas (p = 0.01~. The percentage of positivity of the CEA And of the TPA in the various ~dings of cellular deviation takm different courses; the ~A increases passing from G 1 to G 5 while the tEA presents the highest perhenta~e of =positivity at G 9 both in the adenoearcinomatous and epidez~oid&l fo~ms. The Co57-bleomycin scan m~y be used for the diagnosis oR pulmonary cancer. We determined prospec tively the sensitivity and specificity Of this method for the diagnosis of pulmonary cancer and we have applied Bayes' theorem to our results. We studied 120 patients : 85 with pulmonary cancer and 35 with benign pulmonary lesions, 80 out of 85 patients with cancer had a positive scan. Among the 5 false negatives, there were 2 "in situ" carcinomas and the 3 others tumors were less than 2 cm in diameter. 28 out of the 35 patients with benign pulmonary disease had a negative scan. Among the 7 false positives, there were 4 act{yes tuberculoses and 3 bronchopneumo-nJas [BPN). 2 oatJ~nts with BPN and a RalsR po~i tive scan had a conzro! scan eater 2-3 months, which was then negative. The sensitivity is £A % and the specificity is SO %. OeRining the "a priori" erababilitg oE having lung cancer as clinicalg Iow lid %], medium i50 %) or high [GO %], the "a posterior{" probability oE having lung cancer [p-0/T] in the presence oR either an abnormal saint{gram or a normal saint{gram may be calculated from gages' theorem. We can conclude that : -If the clinical probability (p-C] is low : in presenbe oR a normal scan, p-O/T is close to 1%, while in presence oE an abnormal scan it is close to go %. Thus if the scan is negative we can exclude lung cancer, but iE zhe scan is positive, no conclusion is possible but a second scan after 2 months is recommended. -If the p-C is medium : in presence oP a normal scan, p-O/T is less than iO %, while in presence of an abnormal scan it is greeter than 85 %. Thus if the scan is positive, we must investigate further and iR the scan is negative we san exclude lung cancer. IR the p C is high : with a positive scan, the diagnosis is certain, but a negative scan is probably a false negative. In cases of prostate carcinoma the final decision to attempt a curative radical prostatectomy depends entirely on wether or not there is lymph node involvement. If the lymph nodes contain metastases only palliative systemic treatment should be attempted. The investigation of iocoregional lymph nodes can only be done by histological analysls of lymph node material after a staging lymphadenectomy. TO decide wether the determination of prostate acid phosphatase (PAP) could be of help, the RAP levels were determined in 34 patients on which a stagin E lymphadenectomy was to he performed. The results of the PAP determinations were compared with the histological findings in the removed lymph nodes. There was a high correlation of histologically Rroven involvement of lymph nodes and an elevated level of PAR as determined b y the immunochemical method (EIA) of Merck. In ig of 19 patients without lymph node metastases the PAP concentrations were lower than i.O ~g/l. All of the 15 patients with positive lymph nodes had PAP levels above 1.0 ~g/l. The fact that 3 patients with histologically proven negative lymph nodes showed elevated RAP levels could possibly be explained by involvement of pre-saoral lymph nodes. The pre-sacral lymph nodes are not removed during a staging lymphadeneetomy. These results indicate a new perspective in the use and reliability of PAP determinations in patients with prostate cancer. In order to evaluate different methods for estimating prostate acid phosphatase (PAP) a followup study was performed within a group of 89 patients with histologically proven prostate cancer. The results were related to bone seintigraphy. At operation 56 patients were free of bone metastases (M-) or in remlssion at the time of investigation and 33 patients were regarded as having bone metastases (M+) based on hone scintigraphy. Patients had undergone either transurethral resection and/or hormonal therapy with DES. In a later or advanced stage orchiectomy was performed and/or Androeur therapy given. If possible blood samples were taken every 6 weeks; the maximum follow-up time was 15 months. The different PAP methods were: I. Enzymatic using ~ -n~phtylphosphate; 2. Enzymatic using thymolphtaleinemonophosphate on the ACA; 3. Elisa (Behringwerke); 4. EIA (Merck); 5. RIA (Clinical Assays); 6. IRMA (Hybritech). Altogether 400 samples of 89 patients were analyzed. During the course of the investigation 7 patients were moved from M+ into M-because following treatment no changes in the seintigram occurred and X-ray or clinical examination provided alternative explanations for the abnormalities on the scintigram. All PAP methods had a specificity above 95 percent with sensitivities ranging from 80 to 9E percent, the EIA and IRMA method being the highest. We concluded that the determination of PAP at regular intervals with one of these methods provided a more reliable parameter for posttreatment monitoring of patients with prostate carcinoma than bone seintigraphy. TPA monitoring of 28 patients (pts) submitted to radical Surgery for large bowel cancer was carried OUt during the foll0w-up every two months for detecting early local or distant recurrences,In all cases the diagnosis was controlled by C~ scans, colonscop[ and hepatic 8/1giography. In 4 pts tumor recurrence was observed whereas no evidence of disease was achieved in 24 oases (medi8/l follow-up = 17.5 months). In these 28 pts the difference between TPA and CEA sensitivity rate was high (100% and 25% respectively) and statistically significant (p < 0.05).TPA specificity rate was 79.2% because of the high incidence of false positive cases (5 pts) as compared to the CEA monitoring, that showed only one false positive case and higher specificity rate (95.8%). According to vhe i~nunobiological different characteristics and to present results, the combined use of TPA and CEA dosages seems to be considered very useful, giving an early correct diagnosis in 71.4% out of the patients examined. A timely clinical control of the positive cases allowed the treatment of the recurrences and a better prognosis. It is known, that the results of' ser,~m ferrJtJn assays can be used Bs an aid Jn diagnosis of the tumors 0£ di30 pmol/l) Ct values. The number of patients with high levels of Ct increased in tumors of the respiratory (59%), urinary (54%) and female genital (48%) system, while it decreased in prostatic cancer (5%) and in undetected primary tumors (19%). The number of patients with low levels of Ct decreased in cancer of the urinary tract (6%). These difFerences in the distribution of Ct leveIs were significant (n = 657, X2=34.5, df=14, presulted reduced with statistic si~nifisance (group A p<0.001, group B p<0.01) in the patients with previous myocardial infarction; Accordingly the reduction of the mean EF in infarctuated patients with left ventrieular disfunction (group A) compared to those with good residual contractility (group B) appeared also statistically significant (Pi 1/day. When diuresis is I 1/day and the remaining Ii initially had oliguria. Group 2: 11 patients, in whom acute rejection occurred within the observation period. Five had immediate diuresis; the remaining 6 initially had oliguria. 0nly 2 patients of group i, who showed immediate diuresis, had a normal TTI-value on the first examination. The remaining 15 initially had a low TTZ, which increased with time and reached the normal lower limit between the 10th and 15th day. Renal alloqraft function became adequate when TTI had reached 0.3, so that hemodialysis could be discontinued. In 10 of the ii patients of group 2 at the beginning of ~n rejection episode the TTI decreased and became less than i; in S patients this occurred before serum creatinine incmeased. In the remaining patient of group 2 the decl'ease of the TTI occurred later. We conclude that serial measurements of the TTI are useful for the detection of acute rejection, in particular in cases in whom serum creatinine does not decrease as expected. The following four reagents, destinated to instant preparation for radionuclide lymphatic studies underwent an in vitro and in vivo study : A : sulfur-microcolleid (Solco); 8 : human-serum albumin microcolloid (Nanocoll, Solco);C : antimony sulfide colloid (BYK); D : rhenium sulfur colloid (IRE).The IRE Mo/Tc generator was used in combinaison with all tested products. Stabiiity, pH, amount of free 99mTcOa (as seen by chromatography) were quite simiTar whereas concentration of dry substance and osmolality as criteria gave rather discordant results during in vitro testing.The dianleter of elementary particules of all 4 products, as seen by negative staining on electromicroscopical level varied between 8 and 36 rim,with a general tendeREe to form agglomerates constituted by 2 to 4 subunits. In the famework of in vive analysis, pain following injection (depending on the osmolality), image-quality, number of visualized lymph nodes, target/background ratio, lymph node and liver uptake and extraction from injected deposit have been evaluated,based on qualitative and quantitative criteria of bipedal, internal mammary and axillary ]ymphoscintigrams (140 cases studied). Registered by a whole body scanning camera connected to a computer, total lymph node activity has been expressed as c/sec/mCi injected and measured 3 h after injection over lymph node areas, lhis parameter allowed to characterize the differences among the 4 products,according to age, to presence or absence of edema, to previous irradiation or to morphologically controlled lymphatic pathology. The greatest migration speed and, parallel,the highest total activity over the visualized lymph node areas (40 % extraction from the deposits after 3 hours in normal cases and 25 Z in pathological ones) has been obtained by the product B; whereas A and D showed the most discriminating difference (2,8 to 2,9 times higher fixations-quotient) between normal and pathologic lymph nodes. Laboratoire des Radio-lsotopes, Institut Jules Border, Universit~ fibre de Bruxelles, 1000 -Bruxelles, Belgium. The role of lymphoscintigraphy in determining irradiation fields for breast cancer is assessed. Lymphoscintigraphy associated with 99mTc MDP imaging is the only non-invasive method of obtaining a precise representation of internal mammary lymphatic drainage routes. The first step in this exploration protocol is a chest scintigram realized after subcostal injection on the same side as the tumour of i mCi of 99m-Tc antimomy sulfide. The second step is a scintigram obtained 1,5 hours after a controlateral injection of the same radionuclide. A third scintigram is taken 1,5 hours after intravenous injection of i0 mCi of 99m-Tc MDP. Of the 76 breast cancer patients studied, lymphoscintigraphy identified cross-drainage in 19 cases. In 4 cases, there was no lymphatic visualization. The sulfide colloid was injected again into these 4 patients to make sure that the failure was not due to technical reasons. In all the cases of cross-drainage and in 13 cases where the mammary chain was homolateral to the tumour and was situated more than 4 em from the median line (the limite usually adopted in irradiation protocols), radiation therapy fieldlimits had to be changed as a result of lymphoscintigraphic investigation. This study confirms the great variety of internal mammary drainage pathways and emphasizes the importance of their being precisely localized prior to radiotherapy. Exact anatomical localization in relation to the sternum and ribs is realized with bone scan associated lymphoseintigraphy. When scintigraphic investigation is extended to the whole body, possible bone metastases can also be identified. We have developed a machine allowzng to realize in an optimal way a 99mTc-DTPA deposition into the bronchial tree in respect with the ventilation rate. This machine is called "SEDI IE". As it has been described in the literature, it is well known that this kind of study offers a great sensitivity in the detection of small bronchial disorders. This sensitivlty is very low when we use rare gases such as 81mKr or 133xe. The high sensitivity of labelled aerosol to detect bronchial artefacts is demonstrated by a special kind of deposition where there exist several accumulations of the traceur which are called "hot spots". These hot spots in fact correspond to the local hyperventila~ion existing in same cases such as in severe CORD. The aspect of these images is called a spotty deposition. In cases of bronchial neoplasm, we have noted the existence of only one hot spot. Generally, this hot spot is situated in a bronchus going to an unventilated area. This hot spot is the result of an impaction or a turbulence particle deposition at the level of the stenosis. The existence of a bronchial artefact on this site is always proved by the endoscopy technique. The advantage of a radiolabelled aerosol when nebulized with the SEDI BI resides in the fact that the technique is not invasive and Js very sensitive. The existence of only one hot spot is also very specific of a bronchial neoplasm and in many cases allowed the confirmation of the diagnosis. After Regions of Interest(ROls) were set on the tumor and the normal lung, the mean counts(T: at the tumor, N: at the normal lung) for ROls were measured on both scans, and the Crude Uptake Ratio(CUR) of 2°~Tl to ~Ga(both crude uptakes: T-N/N) was calculated. Adenocarcinomas had a CUR of 1.95±1.41, many of them taking up more =°~Tl than ~VGa. Compared with adenocarcinomas, epidermoid carcinomas had a significantly lower CUR of 0.36± 0.26(p<0.01), taking up more ~Ga than 2°1Ti. Compared with adenocarcinomas, oat cell carcinomas also had a significantly lower CUR of 0.37±0.07(p<0.02), a value similar to epidermoid carcinoma. Adenosquamous carcinomas had an intermediate CUR of 0.9510.19. The 31 patients showed a continuous arrangement from low-CUR epidermoid carcinoma to high-CUR adenocarcinoma. Also, it was found that the measurement of =°~Tl and ~Ga uptakes into tumo~ enables not only a nucleomedical classification but a presumption of various histogeneses in lung cancer. (~d is avidly acclaaulated by LC (Vorne,01~4 23:250 1982) . This work was lhndertaken to evaluate the efficacy of (~H in detecting intrathoracic metastatic spread of LC. In 37 pts.with proven LC we have performed both (~ PS and ~A-67 PS. Each patient received 20 mCi of Tc-99m-~d. The scan was performed 6h. after the injection in Ant.,Post. and Lat.views. In 11 cases ~ SPECT was performed after GH PS. The same day 5 ~Ci of Ga-67 were injected and scan was performed 48h. later in the sane views as with ~H. Both (~ and Ca-67 were positive for metastases in 17 cases. In 5 of these pts. ~4 SPEC~ was performed and it was positive in all of t/le~. In i I pts. both ~H PS and GA-67 PS ~5re negative for metastases and in 2 of them also (~ SPECT was negative. In 9 pts. ~ PS was negative and GA-67 PS was positive. In 3 of these SPEC2 with showed mediastinal and/or hilar involvement and in I it was negative. From these results we can conclude that: 1) C~-67 PS is superior to GH PS in detection of intrathoracic metastases from LC ((~ PS was positive in 65% of pts.with GA-67 PS positive, with an overall accuracy of 76%), 2) SpECT i~oroved mediastinal and hilar a~eg~astases detectability to 77% and overall accuracy of (~ scan to 84%, 3) (~ can be therefore used as a preliminary tool in staging LC. It reduces costs and time and~when positive,can avoid Ca-67 scan and other more invasive procedures. SPECT,when available,lowers False Negative Rate giving a better separation between cardiac blood pool activity and mediastinal nodes uptake. Lancet (Febr. 11~ 1984) .Pr,eviously Shapiro et a]. had described two cases with missing scintigraphic imaging with 131 I-MIBG. In our collaborative study we describe 16 children with neur,oblastoma~ who wer,e investigated with 131 I-oP 123 I-MIBG respectlvily. Some patiet~ had been treated with chemotherapy according to the neur'oblastoma trial NBL-82 of the German Society of Pediatric Oncology. In 1o of these cases enr,ichment of up to 7o% of 131 I-MIBG was demonstr,ated in the tumor as well as uptake of the radioisotope in metastases. In all these cases 24h urinary catecholamine levels were highly increased. Incontr,ast 5 of 6 cases with tlegative scintigpaphic results showed a normal excr,etion of catecholamines~ some of these with and some without evidence of a tumor. Only in t child whh increased levels of catecholamines and a demonstrable tumor-the scintigr-aphic examination was negative. Using the r,esults of scintigraphy, the biochemical values (excretion of catecholamfnes)~ the histology and the stage of the tumor' as well as the therapy we shall try to find a correlation between these panameter,s and the tumor uptake of 131 I-MIBG. In HDA studies data were recorded for 70 min. Images and regional myocardial time activity curves (biexponential fit with calculation of: the elimination half time of the initial phase: T; and the relative size of both phases: C) were interpreted. TI 201 showed a sensitivity of 80% in diagnosing CAD, and a regional sensitivity of 65% in identifying the number of narrowed vessels Residual ischemia is a frequent and serious complication of myocardial infarction (MI). Its demonstration, at rest, requires the combination of perfusion and metabolic criteria to differentiate between infarction and viable ischemic tissues. The purpose of this study was to assess the importance of residual ischemia at rest in a selected group of patients between 10 days to 2 months after the acute MI and to document the reversibility of the ischeraic lesions. Given that several treatments are under evaluation in order to reduce the size oF acute myocardial infarction (AMI), it seems useful to evaluate the effect of standard therapy (ST) (rest, heparin, lidoca{ne) in patients with AMI. 56 patients (PTS) (M : 47, P : 9, Mean age : 45 yr~ with proven AMI (typical EKG, modification of cardiac enzymes) underwent the following protocol : SPECT and RNA at admission and 2 weeks later. RNA allows the determination of ejection fraction (EF). The reconstruction by SPECT of oblique slices oriented according to the long axis of the heart ("short-axis", "long-axis"~ "4-chambers" slices) allows the study of perfusion defects (PD) for each wall (anterior, septal, inferior, lateral, apical Regional wall motion abnormalities (H%~MA) are zhought to he highly specific for CAD although they have been described in aortic regurgitation (AN) and in patients on daunorubicin (DAU) as well. In an attempt to further specify non-CAD RWMA~ consecutive exercise RNV of 17 petients with proven severe CAD were compared with resting ~TV of 24 patients with transmittal myocardial infarction (MI), B8 patients on a critical dose of DAU and 25 ~R patients. Ff~Y~ were defined ob-3actively from paraaletric images by a decreased seegorial amplitude of more than 2 standard deviations of normal. In 15/17 CAD patients (88%) and in 19/24 ~ patients (79%) a significantly decreased regional amplitude was found. Importantly, in all abnormal CAD ~nd MI amplitude scans (100%) a significantly abnormal phase shift in the ssm~e region could be noted. In 6/28 patients on DAU (21%) an apical hypokinesis could he verified. In contrast to CAD, however, the phase distribution was normal in all these DAU patients. The patients with ~/q demonstrated a very inhomogenious pattern. A normal image was seen in 5 patients, 6 p~tients had an infarctlike pattern with regionally decreased ~unplitudes and phase shifting~ 7 patients showed a normal amplitude image with yet regional ph~sic delay, and the remainder 7 patients h~d an apical hypokinesis with normal phase distribution. In eonclusion~stamdardized phase analysis of ~NV data provides a powerful tool for specifying RW~. It allows a highly specific separation of HWZ~ between CAD and DAU patients. The inhomogenious pattern in AR patients can in Dart he explained by increased ~all stress and/or incomplete left bundle conduction abnormalities and awaits further evaluation. and 12/24 received conventional therapy(group B) The time between symptoms and admission/Tl scanning was on average 3.9 fl hrs for both groups.A st 1 slngle-injection(g mCi,i.v.)Tl-sc was perfo[ med prior ST in group A,and for all pts ~epeated 4 hrs later.A second rest-redistribution study was carried on 8 days later.In each pt was deter mined the peak time of CPK from the onset of the symptoms (P-CPK)by serial sampling.Tl-sc was assessed for presence of T1 defect {Tl-d),extension of Tl-d (Tl-~e),evidence of reversibility (TI -r)~d improvement from initial to late study(if -i).Tl-d and Tl-de for each view (ANT,LAO45°,LL) were described by a semiguantitative analysis ha sad on visual classiflcation (N grades).In group A 4/12 pts demonstrated Tl-r and 5/12 Tl-i;5/8 pts with extensive defects had significant impro vement in myocsJ^dial perfusion. In group B 5/12 pts demonstrated mild Tl-r or Tl-i. In pts with extensive defects (S/12) no significant improvement has been observed.Significant difference in P-CPK between pts who had Tl-r or Tl-i and the others was observed:lS°2~4.5 vs 2~.7~4.1 hrs (p<.001).From these preliminary results we conclude that:l)ST in early AMI is associated with significEunt scintigraphic improvement in respect of the control ~2~oup particul~n~ly dn l~ge Tl-de on initial Tl-sc;2)before ruling out myoc~dial salvage a late study as to be performed;g)a better evaluation of the efficacy of ST needs more investigation to clear up the signifies/toe of Tl-r and Tl-i in pts of group R with earlier P-CPK. The diagnosis of cot pulmonaLe and incipient heart failure remains difficuLt to assess ;n cystic fibrosis (CF} on the bas(s of the c[[nical as weLL as the biologica[ parameters. The measurement of the right venfricu[ar ejection fraction has been faciLitated these Last years by the introduction of the radionucLide methods. MeihodoLogica( difffcuLties are however encountered when Tc-99m RBC are used, and are mainly related fo heart chambers superpositlon (equiLibrium method) or the low count density (first pass method). Few papers have been published on RVEF in cystic fibrosis and the results are somewhat contradictory. We have recently introduced a new method for the determination of RVEF, using equilibrium study during continuous injection of Kr-81m in glucose solution. This method offers several advantages related to an increased accuracy and a favorable dosimetry. In 25 patients aged 2 to 23 years with CF, one or more RVEF studies were performed. The severity of the disease was evaluated on the basis of the cLinicaL 5chwachman score, the lung function tests, the ventilation scan and the pa02. RVEF fended to decrease with the progression of the lung disease, although, owing to the spread of the results, no RVEF could be predicted on the basis of the other parameters. The problem of the non-invasive assessment of ventricular and pulmonary artery pressures has not yet been solved. The extent of visualization of the right ventricle during myocardial scintigraphy with 201-Thalliu/n Chloride (201-TI) has been shown An adults and ehildxen to correlate with the pressure of the right ventricle. We replaced 201-TICI with 123-I-~-heptadecanoic acid (123-I-HDA) for myocardial scintigraphy. 123-I has a much shorter half-life than 201-TI and no beta enmlission. This allows administration of a higher dose which gives better counting statistics and, thus, better results. In fourteen children with congenital heart disease, IS3-1-SDA myocazdial scintigraphy was performed within i to 6 days of cardiac catheterization. The age varied from 5/12 to ii-9/12 years, the weight from 5.1 to 29.6 kg. After intravenous injection of the radionuclide (i mCi/10 kg), scintigrams of the heart in the left anterior oblique projection with 5 degrees of caudal tilt were recorded over i0 to 20 minutes. The activity in the region of the free wall of the right ventricle and of the left ventricle was analyzed using a computer. The quotient of IV-activity to LV-activity was compared to the ratio of IV-pressure to LVpressure during catheterization. Statistical analysis of these results gave a correlation of 0.84 (p, 1 rml, resting left ventricular ejection fraction (LVEF <25%), failure to increase LV~ by at least 5 units during exercise. The patients were followed for a mean of 7 (range 4-10) months (34 for > 6 months and 15 for > 6 months) to determine the incidence of cardiac events (cardiac death, acute myocardial infarction, congestive failure, bypass surgery). Eight We have attempted to determine the usefulness of Factor Analysis (FA) in conjunction with the Amplitude image (A) obtained during Phase analysis (PhA). Methods: 13 normals (NL) and 19 patients (pts) all with RI4MA documented by contrast angiography (CA) and 8/19 had in addition T1-2Ol, surgery or autopsy, The algorithm developed by Basin and DiPaola is Based on Barber's calculation of ohlique factors (F) and submitted to a positivity constraint which gives them physiologic significance. Only the ROI corresponding to ventricles was evaluated. A valid result (2,3, or 4F) was considered when no significant negative image was present, nor any zero amplitude type image (corresponding in effect to a Blood pool image). Results: 8/13 NL had 2F and 5/13 had 3F. In all 13 the ventricular F image was identical to the A image and the second F image corresponded to a flat curve and had a LV base "peninsula" or "crescent" and also identified the area of pulmonary outflow tract, In cases with 3F no further split of the ventricular F image was seen and no interpretable pattern emerged from the split of the second image. Abnormals: all but one had 3F. The ventrieular F image of the 2F display was similar to A in 9/19. Those were eases without dyskinesia. In all cases the combined 2F and 3F displays correlated with all or most of the RWMA sites. In 13/19 correlation was Better than phase analysis as far as number of locations and in 18/19 better as far as type of abnormality suggested. In no case was FA worse. This improvement was particularly striking for septal abnormalities and for small dyskinetic areas. FA also suggested abnormality ~n 2 pts where extensive hypokinesia was not detected at all By PhA. Conclusion: FA images used in conjunction with phase and A images improve significantly the detection of RWMA. In a group of mice Prednisolone was administered i,p. in three doses of 2.5 mg during the 24 hrperiod of time before 1251-T4 injection, Another group of animals received four doses of 2.5 mg in the 3 hr-period of time following 1251-T 4 injection. Control animals received only injections of saline. Results of the 3 hr biodistribution study of 1251-T 4 were the following: Prednisolone administration in three doses of 2.5 mg during the 24 hr period preceding 1251-T 4 injection, significantly increased liver concentration of radioactivity from 17.60±I.62% to 23.57+1,09% and intestine concentration from 13.44±0.99% to 18,53±1.37± (p < 0.05) whereas blood concentration was decreased from 20.68±1.08% to 14.70±1.61% (p < 0.05). Repeated doses of Prednisolone from 2 min to 2 hr after the injection of 1251-T 4 significantly increased the concentration of radioactivity in stomach from 1.86+0.26% to 3,36±0.37Z and in intestine from 13.44±0.99% to 17.69±1.21% whereas blood concentration decreased from 20.68+1.08% to 14.5±1,11% (p<0,05). It is thus suggested that high doses of Prednisolone Peripheral metabolism of thyroxine (T4) and 3,5, 3'-triiodothyronine (T 3) and the peripheral conversion ratio (CR) of T 4 to T 3 were determined in S hypothyroid patients (Hypos), 4 hyperthyroid {Hypers), 3 hyperthyroxinemic patients {HyperT4s , 2 familial, 1 amiodarone-induced), and in 13 control subjects with normal thyroid function. 1251-T 4 and 131I-T 3 were injected iv as a single bolus, and plasma activities of ~251-T4, 131I-T3, and of 12SI-T3 newly formed in vivo from labeled T 4 were determined after chromatographic separation on Sephadex G-25. Common turnover and distribution parameters of T 4 and T 3 were determined by noncompartmental analysis, while the convolution method was used to calculate the CR of T 4 to T 3 . AS expected, Hypos had a significantly reduced metabolic clearance rate (NCR) of T 3 (P<0.O0J as compared with the normal controls), while Eypers had significantly raised MCR of both T 4 and T 3 (P<0.0I). HyperT4s showed a reduced MCR of T 4 (P<0.001] and nearly normal T 3 MCR. The T 4 to T 3 CR was markedly increased in Hypos (P<0.0Oll, and nearly norr~al in Hypers and in the 2 familial MyperT4s, while it was markedly suppressed in the amiodarone-induced EyperT 4 subjBct. These results indicate the occurrence in hypothyroidism of some adaptative mechanism(s), whereby the peripheral tissues metabolize T 4 by preferentially producing the more active hormone, T 3. By increasing the T 4 to T 3 CR, the small amounts of available T 4 are thus utilized in the most efficient way. We report this association in two series of retrospectively analysed patients (pts). The first series consists of 28 clinically euthyroid pts showing at ]31I thyroid scan a HTN inhibiting at variable extent extranodular tissue function. Surgical excision of the nodule was performed in all these pts and postoperative histology showed a mierofollicular structure. Serum T 4 concentration was low normal in 5 of these pts (4.7 to 5.4 pg/dl) and quite normal in the remaining pt& T 3 resin uptake was normal in all the pts. The 2nd series consists of 73 clinically eutbyroid not operated pts with NTN at 1311 scan, examined by TSH stimulation, TH inhibition and TRN test& 16 of these pts had relatively ]ow serum TT and TT 3 levels (4.5ei.3 ~g/dl and 1.5+0.I ng/ml~. Six of these pts had serum TT levels lower than normal (2 to 3.7 ~g/dl) and T~. levels from 1,4 to 1.8 ng/ml. Ten years follow~up was performed in one of these pts; TT was constantly low or low normal for 8 years 43.4 to 5.5 Mg/dl) associated to normal TT levels (I.3 ng/ml) Recently 3 serum TT 4 and TT levels were 10 ~g/dl and 2.2 ng/ml respectively; no TSH response to TP~ was observed. The following hypotheses can explain these findings: a) a relative T 3 hypersecretion occurs early in the HTN and inhzbits T secretion by nhe extranodular tissue i 5) HT~ might grow in a hypofunctioning gland and TSH inhibition occurs when TH levels produced by the nodule became equal or higher than those extranodular tissue. is a decreased wash-out of nO±T1 in malignancies. It was our aim to classify malignant and benign tumors according to their biokinetie behaviour. In 35 consecutive pts. with suspicim o~la malignant tumor of the thyroid a 2 T1 scintigraphie sequence up to 40 min were performed. Tn 13 pts,ths final histological diagnosis was performed. 4 papillary thyroid carcinomas were found, 2 with regional lymphatic spread. In 1 pt. with lymph node metastases of a malignant pheochromocytoma a normal thyroid correctly was diagnosted before operation. In 2 pts. with PAP IV cytology, which was not proofed by histology TLTS was normal. Between 3o-40 min al kinds of thyroid tumors aRd metastasis reached a plateau in the 2U±T1 kinetic. The maximal uptake (UTmax) i~ relation to the ~0 min uptake was calculated. As further kinetic parameter peak invasion rate (PIR) and Tmax were defined. A malignant tumor is characterised by a lower UTma x as well as PIR. In malignantand benign lesions at least 2 different groups of vitality (UTma x) can be differentiated. Benign tumors with normal (307=51) and increased vitality (686+_268%) and malignant tumors with normal (163~9) and decreased (106~96) vitality. In conclusion malignant und benign thyroid tumors can be differentiated and classified according to their 2OIT1biokinetic, Further investigations must be untertaken to judge the prognostic value of the described tumor vitality groups. Thyroid mass estimates based on palpation and scintigraphy are misleading especially in young subjects. Therefore ultrasound methods became widely used for objective ~olume determination. Normal in vivo-values for subjects below age 18 are not yet available. Patients and methods: The thyroid volume of 185 euthyroid children (40-210 months) without palpable thyroid enlargement, but living in the iodine deficiency area (WHO II) of Bavaria, was measured by sonography with a maximal error of 11%. Thyroid volume, age, sex, weight, height, basal TSH, T4/TBG-ratto were tested for csrrelation and analyzed by multiple regression, and prediction ranges (95%) were calculated. Results: Thyroid volumes were normally distributed only after transformation of the data (~ VoI). Girls had slightly greater glands than boys in all age groups, even before puberty. As expected there was a correlation between thyroid volume and body weight (r=0,733), height (r=0,745), body surface (r=0,767) and age (r=0,634). The best prediction of the normal thyroid volume was given by the combination of the parameters age, sex, body weight and height. Nevertheless the combination of the parameters sex and height was only slightly inferior but has the great advantage that the relatioeship can easily be displayed in a two-dimensional diagram. For routine use nomograms of the upper l~mlt of thyroid volume based on these two parameters are presented. The data indicate that at least in a region of mild iodine deficiency the pediatric rule of thumb for thyroid mass evaluation (i.e.thyroid mass in grams : years of age) understimates the gland dimension, especiaJly in girls above age 13. Nistolog{cal examlnation of cold sc~ntizraphic nodules of the thyroid is the definite diasnostic test for the differential diaKnosis of malignancies from non-malimnancies. Non-invas[ve tests, such as ultrasonoKraphy (US) have been used to provide a dla~nosJs before surgery. In this study we have attemoted to evaluate retrospectively the efficacy of I~ appearances as an approach to the assessment and management of cold nodules, lan patients with a scintigraphic diagnosis of cold nodules of the thyroid have been examined with fie. All the patients underwent surgery. We re-evaluated their data usin~ clinical records and U~ to compare them with the results of the histological diagnoses at surgery. There were 27 carcinomas (18%] and 121 benign lesions. The US appearances of the nodules were considered essentially for two parameters: the edge of the nodules and the appearances of the texture. The first parameter has not shown any relationship to the malignancy; in fact, of the carcinomas, 30% had a well defined edge, and of the benign lesions~ 47% had an undetectable edge. Multiolicity has not shown to be a criterion for non-maliznancy; in our serie, it had not significative differences between both eaarcinomas and benizn lesions (52% v.s. 3e%). Cystic changes were observed ~n any type of pathology, mainly in benign diseases, hut it was not a typical finding. ~imple cysts were never seen in carcinomas. Decreased echogenicity was commoner in carcinomas, but did not favour maliznancy. Increased or normal echcgenicity was never found in carcinomas. We concluded that: US alone can not be used for distinguishin g malignancies from non-malignancies and the demonstration of a simple cyst by US excludes the possibility of maliKnancy; in fact, US alone was a useful but limited test for differential diagnosis. We believe that the use of clinical data, US and scintigraphy combined together is the most reliable way to screen a nodule of the thyroid. For the treatment of FTA, the results and eomplieations of surgery and 13i-I therapy are compared. 998 patients suffering from FTA were observed from Jan. 1960 to May 1981: Of these, 88 were not treated, 170 had drug therapy, 163 surgery, 577 (all above age 35) 13l-I therapy (dose 517,63 MBq!147.26). Successful results differed significantly between above groups (Tritest p<0.05) Of the 163 surgery patients, only i30 returned for a follow-up cheek. Consider ing also different types of operation, 95 of these (73.0%) had recovered completely. Of the radioiodine patients, only 483 were followed-up and 408(84.5%) were well again. The higher success rate of radiometabolic therapy is statistical ly vet7 significant (two-tailedt test p 95% to be obtained and to reduce the side products to negligible amounts. Commercially supplied kits for sulphur colloids demand either lyophilisation or heating for colloid production. There is some controversy over the degree of quantitative uptake and turnover of such colloids in the liver. One kit with lyophilisate (A), and two kits for heating (B and C), were used for quantitatively measuring tracer uptake and turnover in liver, spleen, lung and peripheral blood, after i.v. injection into patients free from liver disease. Labelling yields of colloids were controlled by chromatography and particle size was measured. Tracer uptake in liver, spleen and lung was quantified with an Anger-type gamma-camera, and an algorithm for attenuation correction showed a relative error of measurement smaller than 10% using an Alderson phantom. Successive blood samples yielded tracer kinetic data for the peripheral circulation. Liver uptake of colloid A was 62%; of B 70%; of C 73% of the amount i.v. injected. Spleen uptake was 15-17% for A, B, and C, Lung uptake, only observed for 8, was 2.5%. Mean blood activity was found to be 17% for A, 2.4% for B and 4% for C.-There was a correlation between the different distribution patterns and particle size. The data indicate uptake values lower than generally assumed for tracers of the reticuloendothelial system. The quantification reported here permits revision of calculated doses to target tissue from various labelled sulphur colloids. While ~-iodophenylated fatty acids are metabolized via B-oxidation~ fatty acids with the iodophenyl substifuent in the side chain are expected to inhibit S-oxidation. Wibh the inhibition of enzymes involved in ~-oxidation trapping of the partially metabolized molecule occurs° The activity therefore is ~etained in the heart muscle cells for a longer period which may produce better myocardial images. acid and 3-phenylpentadecanoic acid were syllthesized and iodinated. The para isomers of the resulting iodophenylpentadecanoic acids (IPPA's) were separated and radiolabeled by iodine isotope exchange with 125-I and I~I-I respective-ly° Various labelin~ teclnliques were examined wifh radiochemical yields of up to 9o%. The biodistribution in rats has been studied with 131-I-IPPA's while scintigraphies of rabbits were performed with 123-I-IPPA's. The results are discussed ~nd compared with radiododinated 15-(piodophenyl)pentadecanoic acid. tested. The analogs mono-iodo-derivative N-(2'-iodo-benzoyl)-cysteine (MIBC), 2',S'-diiododerivative (DIBC) and N-(benzoyl)cysteine were synthesized and successfully complexed with Tc-99m at high specific activity (i0 mCi/mg). Sequential ganuna camera imaging up to 60 minutes in rabbits showed greatest concentration in the hepatobiliary system and rapid clearance from the gallbladder into the intestine. Their biological distributions were compared with that of Tc-99m-N,m~(2,6-dimethylacetanilide)-iminodiacetic acid (HIDA) in 17 different rabbit tissues at IS and 30 minutes after i/v administration. At 15 minutes, the mono-iodo-derivative MIBC showed a greater secretion into the intestine and bile (76.9 2 5.4% dose) than that of the diiodo-derivative DIBC (54.6 ± 4.8%) and even better than the currently used HIDA (60.0 ± 3.3%). The monoiodo analog has higher mean liver activity of 18.0 i 5.4% dose than that of HIDA (13.5 + 2.1%) but lower liver activity than that of DIBC (28.5 ± ].0%). In addition, the kidney and urine activity for both derivatives was similar (5.2% at 15 minutes), but it was four-fold lower than that of HIDA (19.9%). Ttest for differences of hepatobiliary secretion and urinary activity between MIBCand HIUA were highly significant [P<0.001]. It appears that the monoiodo analo~ (MIBC) has better hepatobiliary secretion characteristics compared to both the diiodo analog DIBC and NIDA. It also exhibits less interference from the urinary system. PKIO,169 is a low molecular weight heparin fragment (4,5OOD), obtained from porcine mucosal heparin. This fragment shows an important anti-Xa activity associated with a low inhibition of thrombin. Ladled drug was obtained using stanno~s chloride and Tc 99m pertechnetate. This method is very similar to the routinely used heparin labeling technique. In vitro studies showed a high labeling efficiency (98 %}. Stability of the labeled drug was excellent during 24 H and labeling homogeneity tested by gel permeation was satisfactory. There was no significant difference in Anti-Xa activities of labeled or unlabeled heparin fragment in plasma. In rive in rats, after I.V. infusion of the Tc 99m labeled drug, there was no difference between anti-Xa activity measurements or radioactive countings, beth displaying a plasmatic biexponential pattern (T 1 being 3.04 min, T 2 being 157.5 min). T 2 of the fragment is thus longer than heparin T 2 (66 min). Biodistribution studies showed no thyroid uptake but there are some differences with heparin studies with an important and fast accumulation in liver. This method has the potential of studying various experimental and pathological situations. Since it uses a p~re gamma emetter, short half life radiopharmaceutical, it might be used for pharmacokinetic studies even in human patients, as shown in a volunteer subject. Cam6n. Fatty acid anilides (FAA) contained in adulterated oils have been involved in the ethiopathogenesis of the toxic oil syndrome occurred in Spain in I981. However, their mechanism of action is unknown. In previous work we have reported the kinetic and metabolic aspects of elsie acid anilide(0A). The aim of the present investigation was to define the biological kinetics of linoleic acid anilide(LA). The fate of 3E-LA, given intragastrleally to mice~ was studied using radiotracer procedures and radiokinetic analysis. About 54% of 3E-LA was absorbed. The remaining fraction was detected in 24h feces mainly as parent compound (97%). A fraction of radiotraeer was absorbed via the lymphatic system.3H-LA radioactivity was largely distributed in the organism.Computer-fitted time activity curves showed different tissue affinities (Cmax = 164-14 ng/g of 3H-LA equivalents) followed by a slow monoexponential elimination phase, very similar for most of the organs (30 to 4Oh). 6% of the label remained in the body 4 days after dosing (tl/2 Kel = 62h). Tritium was excreted mainly in urine (40% of the dose). Biliar excretion was of minor importance. TLC autoradiography of urine showed at least 5 LA metabolites. 35% of hidrolyzed urine co-chromatographied with marked paraeetamol. These results are very similar to the previously described for 3H-CA. FAA amide bond are largely hidrolyzed by first--pass effect. Kinetic and metabolic data suggest that the tissue retention might be due to the incorporation of FAA-radioactivity to the cell membrane. K-Strophantosid, /K-Str/ conventional in'ection solution was labelled with ~9Tcm in presence of SnC12 at pH = 2. After labelling the solution was kept at room temperature for one hour. Finally the pH was adjusted to 7 with NaHCO 3 solution. The labelling yield and the radiochemical purity of the labelled product were determined by paper chromatography. Both values were higher than 96%. Biodistrihution studies were performed on healthy CFY rats. The i.v. applied doses were 200 kBq 99Tcm-K-Str in 0.2 ml saline. The rats were sacrificed at 3, io, 60 and 180 min, after injection. The deposited activity in the different organs was determined by dissection and counting in y-spectrometer /Berthold Gamma scint BF 5300/. The distribution of 99Tcm-K-Str in the organs expressed as relative percentage dose/g /RPD/ is summarized in the The availability of a gamma-ll (PDP-II/34) computer system has urged us to couple a ge(Li) detector to this computer for radionuclidie purity control. The ADC system used is a AR-ll, incorporated in the processor box of the PDP-II. The AR-II comprises a I0 bits 16 fold multiplexed ADC system and, in fact is present on all older Oamma-]l systems. To adapt the output of the main amplifier of the Ge(Li) detector to the characteristics of the AR-II a pulse stretcher is used. The conversion of the stretched pulses is started by pulses delivered by a timing single channel analyzer. Since the conversion time of a AR-II is 28 us, the maximum count rate is limited by the hardware to 35 kNz. The data acquisition and analysis program is a modular flexible program which takes advantage of the real time features the RT-II operating system offers. The program is written in Fortran except for the ADC routine which is written in Macro for reason of speed. The maximum data rate the program car handle is 32 kHz. At such data rate the maximum resolution of a Ge(Li) detector is already lost. Since the program is watching the input buffer of the retinal commands can always be given to the program. After data acquisition the spectrum can be stored on disk. For the analysis of the spectra a Tektronix 611 storage oscilloscope is used. The oscilloscope is driven by the program via hardware incorporated in the AR-II module. A set of commands is available to add, subtract~ multiply or divide spectra. Also peak contents, with background subtraction, can be obtained by giving the channel numbers. Due to the modular feature of the program new commands can be defined easily. The 1O bits resolution proved to be enough for our applications. The program showed its value and versatility in the setting up of the production of bromine-75. Recently 99m-Tc(Sn)dextrans have been proposed for lymphoscintigraphy and radionuclide angiocardiography. As we have prepared the lyophilized (Sn)dextran kit for labelling by 99m-Tc at pH>6, for production of high quality radiopharmaceuticals it is important to know the chemical form of tin in lyophilized stannous chleride-dextran preparations. The M~ssbauer spectroscopy has been applied for examinations of tin bonding in lyophilized stannous chloride-dextrans mixture prepared under different conditions: pH, 6% dextran concentration, dextran molecular weights (40000 and fOOD00). The Mbssbauer parameters of hyperfine interaction -the isomer shifts and the quadrupole splittings -are determined. From these values it may concluded that in lyophilized Sn-dextrans the tin appears in two valence states: as Sn(II) and Sn(IV). The Sn(II)isomer shift in products prepared at pN 6,5 are of lower value than that (value) found for the products prepared at pH 2,5. The relative distribution of two tin forms (It and IV) may be estimated. The disscutions deals with the importance of these data for possible characteristics of 99m-Tc(Sn)-dextran radiopharmaceuticals. Boris Kidri~ Institute of Nuclear Sciences-Vin~a, Institute for Radioisotopes ll0Ol Beograd, Yugoslavia * Universit4de Nancy I, Nancy, France ACfD. F. Mata (+), A. PeBaflel (+), Grasses, F. (++) and March, J (++). The introduction of air (oxygen) in the reaction vial during technetium labeling of phosphonate bone imaging agents, may generate pharmaceuticals with low radiochemica] purity. The addition of an antioxldant, such as ascorblc acid or gentlsic acid (GA), has satisfactorily minimized pertechnetate contamination for a long period of time. In our laboratory, when GA (0.56 mg/vial) was used in the formulation of non lyophilized MDP (5 mg MDP acid form, I mg SnCl 2 2N20), coloured compounds appeared when the syntesis of MDP was done at gH=7 and quality control techniques showed and almost to tal failure for ]abeling with Tc-99m, obtainln~ nx>re than 90% of free perteohnetate. We present the studies in order to characterize those compounds in different experimental conditions, such as spectrophotometry and speetrofluorimetry. We found that the above mentioned compound appears quickly in MDP formulations stabilized with GA in presence of an atmosphere of oxygen, showing different chemical features in a pH ran ge between I and 9. Compound does not appear in a pH range between 3 and 6, in an atmosphere of nitrogen or when GA was not added to the MDP formulation. In summary, the liquid preparation of MDP stabi]ized with GA should be formulated at an acid pH and kept in an atmosphere of nl ~ trogen. Otherwise, we risk the formation of oxidatlve compounds with the direct participation of the GA that will preclude labelling MOP with To-gEm. This situation should always be kept in mind in those Nuclear Medicine laboratories that prepare their own home-made kits of MDP-Sn. In doing paired comparisons in ln-l]l tell labelling with oxine Cox), aeetyl acetone (ae), tropol0ne (Crop) and 2-mereapfopyridine-]oxide (mere) using different kinds of blood eells~ ox, Crop and mere proved to be the most potent cell labelling agents. Cell labelling in most cases was carried out on mleroseale: 0.5 ml cell suspension was added to a i0 ml Weaton vial. Under gently mixing 0.15 ml labelling complex was added. Incubation lasted 20 minutes at room temperature. After incubation a sample was collected with a hemafocrit capillary and centrifuged at 500 g. The capiilaries were cut with a glass saw just above the packed cells and the radioactivity of the pieces was measured in order to determine labelling efficiency. Labelling effioieoeies presented were average values of duplicate incubations. The differences between ox, Crop and mere were small with regard boche obtained labelling yields in a sallne as well as in a plasma environment. This was in clear contradistinction to statements from literature claiming a better labelling ability for trop and mere in plasma. Mere inhibited leukocyte motility in concentrations needed to obtain high labelling efficienties. It is reported on recent experiments with FPLC-based purification of monoclonal antibodies out of ascites and of antibody fragments out of enzymatic digests. Irmmunoreactivity after radioiodination was determined by exhaustive absorption with antigen-positive melanoma cells. It was found that F(ab')2 fragments resembled very closely to intact IgG, while Fab showed lower binding rates, especially in antigenantibody systems involving modulation and internalization. The sensitivity of several monoclonal antibodies to radioiodination damage (IODO-GEN method) was evaluated as a function of the amount of iodine attached to the molecule. Two types of antibodies were encountered, one of which showing impairment of intmunoreactivity even at average substitution ratios below one atom of iodine per antibody molecule, the other tolerating higher substitution ratios. Preparations with poor immunoreactivity as determined in vitro localized very poorly to tumor tissue in vivo. The benefit of model experiments for determining the quality of a radioiodinated antibody preparation is discussed. The wide medical application of Tc-99m generators stimulates a new research. It is crucial to get a generator with high elution yields in the smallest volume of the eluate and with high percentage of pertechnetate. The hydrated electrons following the nuclear decay of Mo-99 can disturb elution even in the "dry" column. The redox potential of the hydrated electrons is rather high and it has been found that cupric ion can serve as a proper scavenger for them. The mixture of silica gel and alumina is a good absorbent for Tc-99m generators. This absorbent can be ~mproved with silica gel containing adsorbed copper in the quantity of about 50~g Cu/g. The Tc-99m generators activities up to 74 GBq produced by this method exhibit high elution yields and especially favourable elution profile, Tc-99m being eluted in only 3 ml of eluate. The eluate is free from oxidizing agents and contains 98% of Tc-99m pertechnetate. There are different routes known to produce the Rb/Kr-Generator Here we show, that good results can be obtained applying a new sir~ple technical procedure _Th_e_Ta{_g_et__w_as_p_re_p_a~e_d by-pressing 7 g RbCI (Merck, analytical grade) and packing the obtained wafer in a hollow Aluminium disk. The irradlation at the SIN Cyclotron with 70--80-[A-for-[-h yields between 1.5 and 2 Ci (50-78 GBq) Rb-81 at EOB. The main accompanying nuclides are Rb-8gm, Sr-82, Br-82. There are 15 other nuclides which are clearly identified, but less irc~ortant, because the respective activities never exeed i0 mCi.After the irradiation the Al-disk is cut into two halves and the HbCl is dissolved in distilled water. _The___C~__ner_ato_r__!_s_loaded by passing a measured aliquot of the Rb-81 solution through the colurml, which contains Dowex 50 W cation exchanger and is supplied with two needles allowing the elutien of the generator. This procedure allows the production of 28 generators with i0 mCi at noon Negligible breakthroughs and an elution yield of 80-100% Kr-81m axe the most ia~portant properties of this generator ~iss Federal Institute for Reactor Research, C~-5303 k~renlingen, Switzerland. Although the potentially interesting generators For the ultra short-lived radionuelides have been studied for a decade, almost none of them reached the point of routine clinical application, except of 81-Rb/81m-Kr and 195m-Hg/195m-Au generators. Ihe latter, developed by the authors of this paper, proved to be a very v~luable tool for dynamic studies, particularly in cardiology. The generator consists of s miniature column containing silica gel coated with zinc sulphide on what is adsorbed 580-400 mCi 195m-Hg (f½ 41.6 h). 195m-Au (f½ 30.6 see.) is obtained by eluting the generator with a solution of sodium thiosulphate and sodium nitrate. The performance of the generator (yield oa 29% of theory and radionuclidic purity 0.4, control VS probably has to be performed with valsalva. Dept. of Nuclear Medicine, University Hospital, Catharijnesingel 101, Utrecht, The Netherlands. The purpose of the study was to evaluate radionuclide arteriography in detection of proximal arterial occlusions in lower limbs by correlating it to X-ray contrast angiography, 42 patients (83 lower limbs) with clinically suspected arterial oce~siva disease were included. A 40cm ~ infield gamma camera was placed over the pelvic and femoral region including the aortic bifurcation. A rapid antecubital injection (12 mCu) of Te99m-pertechn~e was done. Serial imaging was performed in intervals of three seconds. X-ray arteriography was performed using Seldinger percutaneous transfemoral technique or translumbar aortography. The results in detection of significant (over 50 per cent) stenoses in the aortoiliac region are as follows. Sensitivity was 27/35 (0.77) and specificity 32/47 (0.68). In case of total occlusion sensitivity was 13/13 (1.00) and specificity 64/68 (0.94). In the upper part of the femoral region the sensitivity and specificity in detection of significant stenoses were 0.57 abd O.80,respectively. The main reasons for low sensitivity in femoral region are that the adductor chanal remained outside of the gamma camera field, and the proximal occlusions interfered the visualisatien of the femoral region. Conclusion: The radionuclide arteriography is a useful noninvasive method for detection of total arterial occlusions in the aorto-iliac region. The diabetic and atherosclerotic patients have shown in previous studies some alterations in ~he ]31I-~b. build up curves executed on the feet. On the other hand new studies have shown in the same patients an alterated haematic and plasmatic viscosity. In the present work we have @cmpared the results of build up curves with ~BmTc-alb. and with 99mTc-erythrocytes on the feet and the data of haematic and plasmatic viscosity of 30 patients (12 atherosclerotics, 12 diabetics, 6 controls). The build up curves have been evaluated through the time (T a) at which they go up "plateau". In the control subjects t a resulted 3'30"± ~5" (right foot) and 4'00" ± 45" (lift foot) at the research with marked albumin, and 4'15" 2 20" (r.f.) and 4'00" • 3O" El.f.) at the research with marked erythrocytes. In the atheroselerotles, instead, T a resulted 9'50" • 4'20" (r.f.) and I0'15"*2'50" (l.f.)in the research with marked erythrocytes. In diabetics the T a resulted 13' ± 2'40" (r.f.) and 12'20" ± 2'30" (l.f.) at the research with marked albumin, and 11'30" ± 3'10" (r.f.) and II'25" ± 3'20" (1.f.)at the research with marked erythrocytes. The T a resulted hlgh significantly different both in atherosclerotic and in diabetic patients compared to the control subjects (p ~ 0.0005). A significant correlation between the T a of build up curve~ with marked erythrocytes and the in vitro haematic viscosity has been found in atherosclerotio patients (p • 0.01). A significant correlation between the T a of build up curves ~ith marked erythrocrees and the in vitro red cells filtrability has been also found in diabetic patients (p~ 0.01). In 1978 In and 1979 In , 1060 Danish patients with primary operable breast cancer were bone-scanned for osseous metastases before entering a nationwide therapeutical trial. A re-reading group interpreted the scans produced in 12 participating hospitals. As s consequence standardized guidelines for interpretation were agreed upon from 1979. The frequency of positive bone scans suggesting bone metastases fell abruptly from 1978 to 1979 as read both locally and by the re-reading group. ~he difference between the interpretations of the local and the re-reading groups remained statistically unchanged. Of the 1060 patients 760 were followed by repeated pro-scheduled scans 6 and 12 months after surgery or until a recurrence was diagnosed. Only 37 of the 760 patients (4.9%) developed bone metastases verified by radiology or autopsy during the first 2 years after surgery. A single positive scan, especially if performed 6 or 12 months after surgery, as well as two or three consecutive positive scans significantly increase the risk of developing bone metastases within 12 months after the latest scan. In 13 of the 37 patients with otherwise subsequently proven bone metastases the scans were negative. It is concluded that a fixed schedule of repeated bone scans in patients with breast cancer is not warranted. In order to study the usefulness of SPECT for detection and localization of bone lesions within the skull, we explored 200 cases. These patients were studied 3-4 hours after administration of Tc 99m MDP, uslng a dual head gamma camera emission tomographic system. The traeerdistribution was visuzaiized in transverse, sagittal and frontal planes. The normal tomoscintigraphic appearance of the skull and variants will be described. After elimination of special patientgroups (bone grafts, orthodontic cases) the data of 125 patients were available for analysis, yielding 56 cases with negative results and 69 eases representing with a total of iBl lesions. Twenty one localizations (16% of the total group) were only visible on scintitomographlc images, hundred and ten hyperactive zones were visible on both. Discrepancies occur seldom In lesions of the cranium (only 4 out of 71), on the contrary lesions of the facial bones (IO out of 29) and the base of the skull (7 out of 17) are frequently missed on the planar images. was false negative in only one lesion out of 49 visible on skull radiographs (eosinophilic granuloma). In the same patients however 59 hyperactive zones were found, indicating as expected, a greater sensitivity of the seintigraphic technique. The distribution of bone metastatic localizations has been studied in 2532 patients with histoloBically proven neoplasic disease, among them 752 cases of breast-ca, 656 lung carcinomas, 295 melanomas, 257 head and neck-,210 digestive tract cancers, 204 lymphomas, 85 prostatic and 73 thyroid cancers. The analysis of the obtained data led to the following statements : -1036 cases (40,9 %) preseeted a proven metastatic attempt of the skeleton. -Prostatic and breast ca. show the highest percent (73 and 43 %) of metastatic bone disease and the most important incidence of spine involvement (80 to 89 % of all metastatic foci).-Lymphumas, melanomas, head and neck carcinomas exhibit about 50 % of metastases localized else ~ where than in the vertebral column. -The incidence of pure spinal metastatic bone attempt remains under 10 % in all cancers studied, except in lung ca. -In 88 g of all positive cases there were multiple pathologic foci in the spine. -16,1% of all spinal metastatic IDealizations (unique or multiple) were identified in the cervical segment, 45,9 % in the dorsal vertebrae and 38 % in the lumbar spine, corresponding to a "from the top to bottom grsdient",the incidence expressed as percent metastase perindividualized vertebra being respectively , 2,29 % for the cervical, 3,82 % for the thoracic and 7,11% for the lumbar vertebrae. -The high degree of the spinal metastatic disease, the differences in several cancers encountered and the existence of the above mentionned gradient support the important role of the vertebral venous system in the etiology and Nst#ibution of bone metastases in the spine. In a study to predict fracture healing, quantitative radionuclide imaging has been performed over both lower legs of patients with a tlbial fracture of one leg. Images were collected at 5 minutes after injection of 2OO MBq Tc99m-MpP (early uptake), considered to reflect bone blood flow, and at g hours (late uptake), considered indicative of both bone blood flow and bone formation. The results were analysed by choosing regions of interest on both lower limbs, "A" being defined as the total counts, normalised for area, in a region around the fracture and "C", the counts in a region of normal bone above the fracture -"B" and "D" are likewise for regions at the same levels but in the contralateral normal leg. The most significant difference (P~O.OO1) between the union and non-union groups is demonstrated using the ratio A/C for the early uptake at 2 weeks after fracture, with little overlap of the groups. A significant difference (P~O.Ol) between groups is also seen using A/B for the late uptake at g weeks, but with a large amount of overlap. This is also the case for the ratio A/C x B/D. Results so far suggest the possibility of predicting non-union in an individual patient with a good degree of sensitivity (87%) and specificity (1OO%). Malignant tumors have been found to show high substrate utilization. Using labeled amino-acids in vivo, tumors exhibited intense activity uptake. This study was undertaken to evaluate whether increased uptake of glutamic acid (glu) is due to increased substrate availability by the blood stream, or whether increased uptake reflects cellular alterations in malignancy. TI-201 (patients) and 1-121-microspheres (MS) or C-11-butanol (rats) were used to give a relative measure of local perfusion. Glutamic acid was enzymatically synthesized and labeled with N-13. In 25 tumor transplants of the rat (5 different tumor lines), identical values were found for N-13-glu uptake and for 1-121-MS retention up to 4-fold control values (r=O.88). Above values of 4, N-13-glu uptake exceeded the MS retention. However, when a diffusible flow tracer was used (C-11-butanol) in these tumors (N=4), flow paralleled glu uptake. In 12 patients, N-13-glu and initial T1-201 uptake by 9 malignant and 3 benign lesions was determined. No systematic differences hetween flow and substrata uptake was observed (r=O.92) within a range from 1.5-9.5-fold uptake as compared to a normal control area. Different from in-vitro conditions, increased substrate utilization by tumors appears to be enabled and controlled by vascularization. Therapy conditions are being investigated. PET has been shown to provide quantitative information on the biodistribution of positronemitting radiopharmaceuticals. Using carbon-ll labeled amino acids it should he feasible to study metabolic aspects of tumor growth by measuring amino acid transport and possibly utilization. This concept was tested in 74 patients with either cancer of the pancreas or other malignant tumors. Two essential amino acids, tryptophan and valine, as raeemic mixtures and in the natural L-form, and two unnatural amino acids, l-aminoeyclopentaneearboxylie acid (ACPC) and its eyclehutane analog (ACBC), were used for these clinical investigations. A modification of the Ddcherer-Strecker synthesis technique was employed for labeling the amino acids with earbon-ll and an ECAT-II(TM) scanner provided positron tomegraphic images. The results overall gave an 82% true positive rate and indicated that these amino acids appear to be particularly useful for studying cancer of the pancreas and brain tumors. In view of the relatively poor spatial resolution of currently operating PET imaging devices, this technique is not yet likely to be of significant value in the early detection of cancer. However, non-invasive positron tomographie determination of amino acid uptake by tumors lends itself to provide information on tumor growth and may therefore be of therapeutic and prognostic value for the cancer patient. was ~sed in follow up studies of regional blood flow (RBF) and oxygen metabolic rate (ROMR) in six rabbits implanted with V2-tumor in tigh. Measurements were done before the therapy, one day after the last treatment and one week later. Therapy consisted of 2400 reds giv~ in 3 fractions on consecutive days. C 02technique was also used to study changes in RBF in tumors in 8 patients undergoing therapy. Measurements were done before therapy, at the dose level of 5000 rads and in 2 patients 2 weeks after the therapy. Blood volume correction was done using either IIco or 68GaCI 3. According rabbit studies the RBE increased in tu/nor from 15.2±2.3 ml/min/ 100cc to 29.7±17.8 ml/min/100cc because of radiation. One week after the therapy the RBF was 9.8±4.3 ml/min/lOOcc. In normal tissue the corresponding values were 4.5±0.5, 9.9±4.3 and 6.3±2.6 ml/min/100 cc. The value of ROMR decreased in tumor during radiation from i07~67 to 71±4~moi /min/100cc. One week after the therapy the ROMR was 69~38 @mol/min/lOOcc. In normal tissue the corresponding values were 20±9, 41+25 and 34~4 ~mol/min/100cc. In human studies the tumor blood flow increased at a rate of 4-5 % per day during radiation and in 2 patients studied the blood flow decreased after the therapy to the level prior to radiation. This kind of approach will give understanding of biological behavior of tumor. On the base of radiosensitivity it seems important to take account changes in RBF and ROMR within tumor during radiation therapy. University Central Hospital, Meilahti Hospital, SF-00290 Helsinki 29, Finland Massachusetts General Hospital, Boston A360 PANCREATIC FUNCTIONAL PCT IMAGING USING Zn-62-EDDA. Y.Fujibayashi, A.Yokoyama, I.Yomoda, K.Horiuchi, H.Saji and K.Torizuka. In our early findings, high pancreas distribution of radioactive zinc(an), if administered as Zn-EDDA(Ethylenediamine-N,N'-diacetic acid) has been achieved. As Zn is closely associated with exocrine and endocrine functions of pancreas, exploitation of Zn metabolism for an anatomical and functional diagnosis was conceived, namely with the recent availability of positron emitting Zn-62 (half life = 9 hours). In the present paper, response changes in gn biodistribution (mice) and Zn excretion through the pancreatic duct (rats) to the stimulation of gastrointestinal (GI) hormones (exocrine stimulation) like secretin, CCK-PZ and glucose (endocrine stimulation) were stud led. Under these stimulus, tissue biodistribution in mice injected with gn-65 (half life = 270 days) showed pancreas specific decrease of radioactive Zn whenever GI hormone was post-administered; whereas glucose lacked effect. Also the pancreatic secretion of radioactive Zn (pancreatic duct cannulation, Love's method) showed increased Zn secretion only under the CC~-PZ effect, 3 hrs post Zn-65 injection. Thus, the effective mobilization of the injected radioactive gn, upon exocrine stimulation, represented by CCK-PZ, favored the exploration of functional study of the pancreas with the positron computed tomograph (PCT) using zn-g2-EDDA, in dog. Great evidence of the applicability of this system in regional function studies of pancreas was obtained. In vivo demonstration of Zn participation in the exocrine function of the pancreas holds considerable promise. ECT with 1-123 (p,5n)[3-4mCi) labeled F(ab') 2 fragments (1.5mg) of monoclonal anti-CEA antibodies (NO 202 and 35) was performed in 14 patients {4 primary, 3 recurrent tumors, ii metastatic diseases) 6,24 and 48h after injection with a dual head rotating camera device. Tumor to normal tissue (mucosa, serosa, fat, blood) activity ratios could be measured on surgically resected material in 4 patients. These ratios were 6/8/15/9 with F(ab')2MAb 202 {n=l) and 1.3-3/4.7-7.7/4.7-15.5/0.5-2.2 with F(ab')2MAb 35 (n=3). All primary and recurrent tt~nors were visualized by ECT, the best images being obtained 24h p.i. 2/2 small lung metastases in a patient under chemotherapy could not be demonstrated. Of the eight patients with liver involvement 4 showed clearly positive, 2 equivocal and 2 negative ECT images. Image contrast was enhanced on the 48h pictures in the positive cases, 2 of them having cold areas on the 6h scan which gradually "filled up" later on. 2 patients presented g bone metastases, 6 of them being detected on the planar images already, 2 dorsal metastases {D6, DE) could be distinguished from thoracic blood pool by ECT only. Thus 19/25 tumor sites were correctly localized whereas 2 remained equivocal and 4 negative. The major advantage of this method rests in the high quality of the images which permits to distinguish tumor accumulation from physiological organ concentration and circulating antibody without artifacts inherent in subtraction techniques. relapses. 0nly those patients with primary colo-rectal carcinomas, with or without hepatic metastases, for whom a laparotomy for hepatic surgery or preparation for intraarterial infusion is planned are admitted to the trial. Therefore, in each patient immunoscintigraphy is followed by tumor tissue examinations both by radioactive measurements and by immunostaining. Although the data thus far collected from this ongoing study are insufficient to draw conclusions as regards the main goal of the trial, some remarks may be made about the methods used for such a study. These remarks derive also from our previous experience with anti-melanoma MoAb and F(ah')2. Subtraction techniques are applicable only in particular conditions, whereas SPECT appears ta be a ~re suitable technique to study depth localizations, l~munostaining, performed within a short time after scintigraphic examination in our laboratory, makes it possible to quickly establish for each patient a correlation between the scintigraphic results and the reactivity of the examined tumor for the employed MoAb. In this way, it is possible to obtain an accurate selection of true-negative and true-positive cases. Polyelonal antibodies were raised in rabbits against the main human prostatic acid phosphabase (PAP) (enzyme A, pl 4.9), purified to homogeneity. The antibodies were purified by affinity chromatography using i~obilized pAP, and Feb fragments were purified on protein A Sepharose. The antibodies or their Pab fragments were coupled Co diethylene triamine enta-acetic acid, and labelled with 99mTc or ? illln. The labelled derivatives retained their i~unologieal reactivity with PAP in vitro. The doses of radioactivity and protein injected into patients with prostatic carcinoma were 0.7-11 mCi and 50-500 pg, respectively. The nine patients investigated so far had T3r 4 NxM I prostatic carcinoma. Six patients were injected with an antibody labelled with 99mTc, one with a Feb fragment also labelled with 99mTc, and two with an antibody labelled with lllln. The metastases, including those in the bones, which had been observed in the patients using X-rays or bone seintigraphy, could he visualized with the immunoscintigraphie techniques used. In addition, in one of the patients studied, a distinct incorporation of radioactivity was also observed in the left inferior scapular region, which was not seen by conventional bone scanning, hun was later confirmed by X-ray studies to be a metastatic process. Immunoseintigraphy of prostatic carcinoma is a promising approach and needs further evaluation. Prospective studies a~e needed to evaluate the clinical eIficaoy of radioimmunolooalisation techniques if they are to develop into routine practice. Monoelonal antibody against human milk fat globt~e antigen HI4FG2 is active against an epithelial surface antigen lining ovarian follicles. Using the Iodogen technique HMFGg was labelled with 123i. After completin~ a pilot study in 25 patients successfully, we report a prospective study in a further g6 patients with suspected or oor~firmed ovarian carcinoma. Dynamic imaging was undertaken, then static imaging at 10 mln. 4 h and 22 h usi-~ a computer linked gamma camera. After patient and computer aided ~epositdoning techniques, target to non target ratios were improved where necess~ usir~ E proportional s~btraobion of the i0 rain f~om the 4 h s/Id 22 h images. Followi/l E the study the patient went for surgel 7 and these findings were recorded independently. A good co~relation was fotn%d between radio-in~unoseimtigraphy and the sumgioal findir4Es in 17/18 patients with malignant ovarian turnouts. However good uptake occurred in 2 benign ovarian tumolrcs, 1 fibroid and 1 hopetome seconder 7. Equivocal uptake was seen in 4 non ovs]0i~n tl~moztrs. The results ~uggest that the technique should not he used to screen pelvic tu~ours but that in known ovarian ca/leer sta~ing is helped and the :seoond look' operation to assess chemotherapeutic response may be avoidable. A favourable region for RIS represents the lower abdomen with it's only slight problems of backgroundactivity. There= fore carcinomas of the genitourinary tract as well as colorectal carcinomas gives a good target for RIS. All of the patients we investigated were operated a few days after carriing out the scans. The patients were either suspected of having a primary ovarian cancer or a recurrence, respectively. All tumor sites including metastases, which were recognized by the scans could be found at the operation. So the pro dictive value of the method was very good. Thinking on the problems of ovarian cancer diagnosis and treatment we assume that there will be the greatest useful= tess of RIS. Our results showed clearly, that RIS is able to reveal tumor sites which may not be detected by other methods, especially in the region of the lower abdomen. The tissue distribution of monoclonal preparations was evaluated in patients (pts) not affected by the ttrmor for which the antibodies were specific. Clone F023C5 (IgG I) was specific for CEA and 16B13 (IgG2a) for human lung tumors. Whole IgGs and F(ab') 2 (Feb) were labeled with 1311 (iodogen moth od), at specific activities of 8-20 mmi/mg. The kinetics of 13tI-F023C5 IgG and Feb were studied in 4 pts each, and 1311-16B13-Fab in 5 pts. Plasma disappearances, whole-body imaging, liver and spleen uptakes were evaluated daily up to 6 days; a computerized gamma-cap,era was utilized. Following similar early kinetics of distribution [=45% of initial activity in plasma at 24 hrs), FO23C5-Fab showed a faster decay than IgG: terminal T~ 50.3 ± 6.2 versus R8.0 ± 11.7 hrs. No significant differences were found in the liver and spleen uptakes, that were moderate for both tracers. With ~40% of initial activity in plasma at 24 hr~, 16B13-Fab had a termin~l T~ of 6Q.2 ± 6.3 brs; t6B]3-Fab consistently showed a relevant uptake in the normal lungs, of approximately the same degree as in the liver and spleen. The results obtained show that no advantages derive from the use of Fab versus whole IgG with clone F023C5. Clone 16Bl3 does not appear to be suitable for lung tumor immunoscintigraphy, due to the important in vivo uptake by normal lung structures, despite the virtually absent cross-reactivity with normal tissues exhibited in vitro. The highly selective uptake of meta-iodobenzylguanidine (MIBG) permits a specific radioisotopic therapy for pheochromocytoma. Except single case reports there are no specifications about the achievable radiation dose in the tumor tissue. We therefore performed a systematic analysis to determine these values. During scintigraphic examination of pheochromoklnetlcs of 1311 cytoma " " -~IBG were studied in 9 patients, 7 of those suffering from a benign, g from a malignant pheochromocytoma. Maximum uptake and effective half-life were measured by gamma-camera. The tumor mass was evaluated by CT. Using these data the radiation dose accumulated in the tumor tissue was calculated and related to I mBi of applied activity (20-4o rad/mDi). In the 2 patients with malignant pheochro~Q~ cytoma a therapy with high activities of i~il_ MIBG was performed. The values of half-life and relative uptake in the tumor measured during therapy fitted well with the diagnostic data: linear relationship of applied activity was found when compared with tumor dose. An intensive tumor uptake of 1311-MIBG could also be demonstrated in a patient with neuroolastoma. Measurements using tracer activities showed a relative maximum uptake of more than 3o% and a half-life of 56 hours. In that case a selective radioisotopic therapy seems to be possible as well. One can even expect a higher therapeutic efficiency as the neuroblastoma is known to be more radiosensitive than the pheochromocytoma. Zentrum Radiologie der Universit~t Heidelberg In the patients with d[fferent{ated thyroid carcinoma usual procedure after surgical treatment is rad[oiodine ablation of residual thyroid tissue. Metastases which accumuiate iodine are also treated with 131[. In 42 of these patients sailvary gland scintlgraphy was performed using 7.qMeq/kg 99mTe~pertechnetate before and after stimulation by D vitamin, in order to determine possible damage of the salivary glands. The patients were divided in three groups: the first group included 15 patients with residual thyroid tissue before redioiodine therapy; the second -20 patients treated with 2.96-3.7 GBq 13]1; the third -7 patients who had received over 7.4 GBq I3fl. In order to observe the influence of TSH on salivary gland function scintigraphy was per-Formed ~n g patients both on and off replacement therapy. In the patients of the first group normel salivary glands function was found. 11 patients in the second group revealed slight deterioration in accumulation in and excretion by the salivary glands. The influence of TSH was not found, In all patients in the third group abnormalities in salivary glands function was observed: from severe functional impairment to complete nonvisua]ization of the glands. In three of seven patients who were followed-up in longitudinal studies slight abnormalities in salivary glands function were established after first radioiodine therapy (2.96-3.7 gBq 1311). We found significant impairment of salivary glands Function which depends of the radioiod[ne dose received. In the study that is under way we intended to reduce the [mpalrment of salivary glands function by frequent stimulation of salivary excretion after rad[oiodlne application. The results obtained with an integrated treatment (I-131-therapy, external radiotherapy,surgery and chemotherapy) in cases of metastatic thyroid cancer over a 15 years period (198e-1983) have been evaluated• Out of 258 cases of proven thyroid carcinoma, 56 developed distant metastases. 35 of these cases were histologica! ly differentiated (18 of papillary and 27 of follicular type); io cases were undifferentlated and 1 case was of medullary type. The metastatic process affected the lung in 40 cases, bone zn 32 cases, brain and liver in 2 and adr~ nals in one. 24 patients had a single lesion, while the remains displayed multiple site metastases. From the therapeutic point of view, the key role of radioiodine therapy in treating lung metastases in which a favourable outcome in almost all cases (87.6%) occurred must be emphasized, as well as the role of the combined 1-131-therapy and telecobalt therapy in skeletel metastases. Also the surgical removal of af fecte@ bone segment was successfully used in 6 cases. Chemotherapy gave some benefit as a complement to 1-131-therapy in patients with reduced oz absent radioiodine uptake. In the undifferentiated and medullary metastatic tumors the integrated treatment was only temporarily effec five. The iO years expected survival rates (actuarial analisys) in the investigated series was as follows: The effect of some factors affecting survival in differentiated thyroid can-care limited to the thyroid (TI-T3 ITO ~i0 stages) following preventive thyroid ablation was studied in a group of 326 patients followed for I to 26 years. The absence of any extrathyroid tumor was proved by surger}j, scintimraphy in the course of thyroid ablation, and b~ scintigrephy in the phase of induced athyroidism. ~he crude survival (not corrected for see) was in the whole group 0.953/5 years, 0.833/10 years and 0.611/15 years. 14 patients died of thyroid cancer I to 15 years following treatment. The effects of age ( under and over 40 years), TI, K:I classification (T I+2 vS. T3 syndrome), of dose administred to thyroid in Oy end that of the type of surgery ~TTE vs. all other types) were found to be significant at the 5-and 10year intervals. The influences of sex, microscopic classification (papillary vs. follicular cancers), of ~qount of 131 I in GBq for thyroid ablation and of the postsurgical scan were not significant. It is believed that prevsntive thyroid ablation is an important step in the complex treatment of differentiated thyroid cancers, but its limitations should be kept in mind. Positron emission tomography (PET) of energy metabolism of the brain in man using 2-18-F-deoxyglucose (YFDG) does not distinguish between local perfusisn, facilitated transport and enzyme catalysed catabolism. In contrast, ll-Cmetbylglucose (CMB) permits separate measurements of facilitated transport (FT) and local perfusion; in conjunction with 2FDG, it promises information on enzyme catabolised eatabolism. The compound 3FDG is known to behave kinetically similarly to CMG. This paper reports on FT for CMG and 3FDG. After informed consent, twelve patients (P) with ischemic brain disease, 9 P with initial and advanced Huntington's chorea and 10 normal individuals (ND) were examined by PET after i.v. application of 5 mCi of CMG or 3FDG. In each P, 30 transaxial images were registered in I selected plane, image collection time being I min. Timeactivity curves were created from different regions of interest. The ratio of tissue concentration to tracer steady state between tissue and blood yields the perfusion-independent rate constant of FT from tissue to blood (ky). In ND, k 2 for CMG was 0.24 + O.O3/min, as expected, and for 3FDG, 0.47 + O?O7/min indicating a higher FT capacity for gFDG than CMG. In acute ischemic brain disease k~ was normal or reduced at the site of insult fob both CMG and 3FOG. In contrast, P with chronic occlusion of the middle cerebral artery had an increased kp. In Huntington's chorea, kp was reduced in th~ basal ganglia but normal br occasionally significantly increased in frontal or occipital cortical areas, for both CMG and 3FDG. Thus, CMG and 3FDG have different values for k~; however, the relative changes induced by pathology are similar for both. It is suggested that CMG or 3FDG can be used for determining the lumped constants necessary to apply 2FDG to analyze energy metabolism of the human brain. In eiqht patients with schizophrenia in different stages and severity without any demonstrable vascular changes and normal transmission computed tomography findings as well as normal neurological examination IMP-Spect was performed. In all cases lesions of different size and location were observed. Patients whose symptoms were improving showed small localized areas of reduced uptake of IMP distributed all over the brain. In patients with severe symptoms of the disease extensive defects involving mainly the subcortial and central region with occasional extension into the cortex and in addition involving the region of the basal ganglia were seen, Defects in the region of the hypothalamus seemed to be of special importance not only for the assessment of the extent of the patients disease but also with respect to the patients prognosis. Reduction of the IMPuptake in the hypothalamic region correlated with an unfavourable prognosis of the disease. It is concluded: IMP-uptake defects can occur without corresponding vascular changes or anatomical destruction of the brain in patients with schizophrenia. The size of these IMP-lesions correlates directly with the clinically stated severity of the patients mental abnormalities. A lesion in the hypothalamic region may allow prognostic statements. Studies on schizophrenia using IMP-Spect should therefore be carried out fur~eron Univ,-Klinik f~r Nuklearmedizin Innsbruck, Anichstr. 35, A-6Q20 Innsbruck The metabolism of ll-C-methionine has been studied in a small series of patients using the model described by Bustany et coll. The metabolic pattern was compared with the findings on CT and PET using 68-Ga-EDTA and also to the histology of the tumours. PET with ll-C-methionine has already become an important method in the clinical management of brain tumour patieets. Particularly tumours with a high degree of differentiation are better delineated with ll-C-methienine than with the other techniques used. The compartment analysis suggests that the accumulation of ll-C-methionine is related to the protein synthesis, which in the majority of the patients was considerably higher in the tumour than in surrounding brain tissue. However, considerable variations were noted in tumours with similar histologic patterns. The implications of the findings on determination of prognosis and on choice of treatment still remains unclear. It is probable that increased knowledge of the biologic character of tumours will increase the possibilities of successful treatment. Hospital, S-104 gl Stockholm, Sweden. Tc-99m labeled propyleneamine oxime (PnAO) I, 2-dithia-5-8 diazacyclodecane (BAT) and their analogs are lipophilic radiopharmaeeuticals that cross the blood-brain barrier. These compounds and several analogs were imaged with single photon emission computed tomography. Siuee ~ny of these current compounds have short residence times in the brain with T~ as low as two minutes, initially a modified Harvard Multidetector brain system was used. This system permits a high sensitivity, high resolution image of a single slice to be obtained in 54 seconds. Sequential data were collected from the single slice device to generate washout data and slices were summed to obtain images of these agents in baboon and man. Images obtained demonstrate brain uptake early after the IV injection of these compounds, but subsequent redistribution into muscular structures in the baboon model. In the patient studies obtained, early images (1-5 min) show grey matter uptake. One analog, Tc-99m BAT-eyclohexame, with a ~ in brain of 102 min was studied with Siemens ZLC 37005 rotating gamma camera in a monkey model. Work is in progress to investiHste analogs of these compounds with a more favorable residence time in the brain that would warrant further patieat studies. This study emphasizes the need for either a radiopharmaceutical with prolonged brain retention and fixed distribution or a high sensitivity SPECT instrument able to do rapid scans if a Tc-99m labeled radiopharmaaeutical for brain perfusion studies is to replace the 1-123 labeled amines. In order to assess the ability of three classical methods and a new method to correctly register thallium images, we apply those methods to thallium images with artifical defects simulating myocardium lesions, glmulated defects are adjustable in location, size and intensity. Differences Iterative attenuation correction algorithms which use projector-baekprojeetors that mode] the attenuation process are found to more accurately quantify the source distribution than presently used filtered backproiection algorithms which use preprocessing or oostprocessing attenuation correction techniques. For an iterative algorithm to be feasible in a clinical setting two things are required of the projection and backprojection operation: i) it must be efficient and 2) it must pronerly model the attenuation process. A new ray driven projector-backprojector has been designed, for hardware implementation, which models the attenuated Radon transform of a source distrihuted within an attenuator as line integrals of discrete pixels representing the source and attenuation distributions, Attenuation factors are calculated for each oixel during the projection and baekprojection operation instead of storing preealculated attenuation factors on disk or in large resident core memory. The attenuation factors are calculated from the digitized transaxial image of the attenuation distribution which is stored in core for efficient access during the projection and baekprojection operation. The reconstruction of the source distribution is obtained by using an iterative algorithm such as the conjugate gradient which requires one projection and one backprojection operation for each iteration. The projector-backprojector can be implemented with enough parallel processing to accomplish multi-slice reconstructions in a few seconds. For the management of patients (pts) with unilateral renal artery stenosis (NRAH) the relative hippuran uptake (P~U) of the affected kidney is important. However, P~U depends on the regions of interest (ROT). To elucidate the influence of the size of kidney ROI (KROI) and the place of background ROI (BROI) on RHU, renographic data of 49 by angiography proven URAS-ptS (24 leftand 25 right-sided) and 8 essential hypertensive (EH) pts were reproeessed. These data were obtained using LFOV-ga~nacamera and radiohippuran. ~ROI were generated automatically on the first 5-min frame in 64x6d matrix by determination of the distinctive intensity of the image. RHU of the affected kidney (RRUA) in NP~S-pts and EEU of the right kidney (RHUR) in EH-pts, calculated from the activity in the 2nd min using BROI between the kidneys were 31.4+10.7% resp. 49.9+ 2.3%. When fixed BROI below the kidneys was used, every enlargement of both KROI by one pixel rim resulted in an increase of RHUR by 0.5~0.6%. Compared with BROI between the kidneys, using BROI semilunararound the kidneys, correcting for each corresponding kidney,resulted in a decrease of P~UR by 2.1+2.2%. These findings indicate that the background activity of the right kidney is higher than of the left. Enlarging one KROI by one pixel rim always resulted in an increase in RBU of the corresponding kidney, although the increase is smaller if BROI was chosen between (0.8%0.8%) instead of below the kidneys(1.7+_0.7%) In comparison with BROI below the kidneys, using BROI between the kidneys had no influence on the RHU of EN-pts, but it did decrease the RHUA of URAS-pts by 1.7+i.5%. Thus, the size of KROI has less influence on RHU when BROI between the kidneys is used, moreover the discriminating capacity of ~U is probably increased. We can recommend this algorithm for the generation of KROI and the use of BROI between the kidneys, which also can automatically be deter-~ined. Dept. of Nucleaz Medicine, University Hospital, Catharijnesingel 101,Utrecht, The Netherlands. FOR TEE MEASURE-MENT OF CIRCULATING INSULIN ANTIBODIES: DISCOR-DANCES ETWEEN THE OBTAINED DIFFE-12 ~ 3 RESULTS WITH RENT I-INSULINS (porcine,bovine and human) . D.J. Hartmauu,A. Cotisson and G. Ville Following parenteral administration of insulin~ insulin antibodies are detectable in the sera of most diabetic patients. We have used a second antibody-PEG precipitation assay specific for human IgG insulin antibody after a first incubation step with different labeled insulins. Monocomponent insulins (porcine,bovine or human) were labeled with iodine 125 using the chloramine T method. 20pl of Ratient's serum were incubated with 100pl of Iz5I-insulin at +4°C for 24h. Then 100pl of anti-human IzG goat serum and I00~I of PEG (final concentration: 2 p.cent,w/v, with 0.04 p.cene Tween 20) were added. After a 5 min incubation at room temperature Iml of distilled water was added. After a ceutrifugation at 2500g for 20 min,the supernatant was discarded and the pellet counted for radioactivity. With the three tracers,we studied normal and diabetic subjects ; sera from ~reaeed patients demonstrated binding ranging from I to 92 p.cent, The antibodies recognized antigenic sites shared by the three insulins: in general a same serum demonstrated similar binding with porcine and human insulins and significantly higher binding (about 4 p.cenC) with bovine insulin. However in few cases (0.8 p.cent from 1954 diabetic patients) a greac discordance was observed: the difference of binding could reach 50 p.cent. For these sara,competitive binding,after the dissociation of immune complexes,showed preferential binding to bovine insulin and partial cross reactivity for human or porcine insulin,in con-~rast to ehe other seza which showed total cross reaetivities for the three molecules. The determinations of the antibody affinity constant and the free insulin level can be useful to explain the differences observed on a same sara with the three tracers and to appreciate the changes of the insulin antibody levels after a modification of the therapeutics. The incidence of circulating immune complexes (CIC) has been ascertained in various diseases as autoimmune diseases, infections or malignancies. We report the ootimisation and the characteristics of a ~25I]CIq binding test in liquid phase for the detection of CIC. C1q was isolated from human serum in the presence of ENTA using successive precipitation steps at low ionic strength and was enzymatically radiolabeled with iodine 125 using a ]actoperoxidase method. The iodination yield was about 90 % and the specific radioactivity obtained was between 1 and 2 ~Ci/pg. 50 pl of patient's serum were incubated with 100 pl of 0.2 mol/l EDTA pH 7.5 at +37~C for 30 min and after were placed in anice bath. Then 50 D1 of {128I C1q (SO ng; 68000 cpm) and I ml of a 3 % polyethylene glycol (PEg) solution in borate buffer pR 8.3 were added. The mixture was left at OOC for 90 min and centrifuged at 1500 g for 20 min at + 4°C. The supernatant was completely discarded and the precipitate counted for radioactivity. The results were expressed as per cent of precipitated 125I C1q as compared with the [1251]Ciq radioactivity precipitated by 20 % TCA. The optimisation of this ~25I]CIq binding test has lead to the following conclusions : I) An 90 miu incubation at O°C is needed to reach the equilibrium of the reaction. 2) A 2.5 % final concentration of PEG must be used to obtain optimal discrimination between aormal donors and patients sere. 3) Blood must be collected without any anticoagulant. 4) Sere can be stored at + 4°C or at room temperature for a week, at -2O°C for several weeks without any modification of the results. Repeated freezing and thawing can be performed without any damage. Many sera of patients with systemic lupus erythematosus or hepatitis contain detectable levels of CIC. This test is routinely employed, specially in the case of treatment by plasmapheresis. Centre de Radioanalyse, Institut Pasteur, 13-15 rue Domer 69007 LYON (FE~NCE). CLINICAL SI(~IFIC#~CE OF SERUM A~ $YNOVIAL FLUID FERRITIN IN ]2~FL~ATORY ART~TIDES. 0 Di ~%m%no, M. Fer~e~hini, N.G. Toni, P. Scatena, P. Migliorini, g. Tartarelli and S. 5~nbar dieri l~y repor~ indicate la~e qusntitie~ of Fer~itin (Fe) in synovial fluid (of) of patients with ir~fl~tory a~itides. ~hiS Fe mi~it reflect local hyperproduction of type A reticulo~thellal cells of the synovial membrane or might be released from synovial cells dansged by local flogomis. In this view sf was collected from 2/ P. with 06teo~is (OA, lbM~)and 73 p. with ~heumathid or Pseriathic Arthritis (RA, PA, 32 M-41F) classified according to ARA criteria. ~mong RA-pA p. on clinical (Ritchie's articular index) and laboratory (abrmrmal ESR, CRP, ~o) 8~c~, 39 p. were defined active. The parameters considered were in serum (s) ESR ~nd Hb, in sf (7~50, }~ titre~ cell count and im1~ne complexes. S and sf Fe was determined using a RIA system based cn antibodies ~inmt ~k~an liver Fe (Lisop~ Lepetit MiLgn). S Fe was r~ot si~ificsntly different in p. with P~PA (IS6+ 17.5 mg/ml, m~_ SEM) and in CA (I08.2+2/.~, si~ificantly high er levels were found in active vs inactive F~-PA p.(p~O.025). Sf Fe was significantly elevated in RA-PA p. vs OA p. (2/~0,9~-+22.8 VS 180.7+28.1, p~O.O2) and in active vs inactive. ~ S and sf Fe ~as higher in males vs females RA-PA p. (p5~UI/ml The biological rhythms of serum concentration of total and free fractions of cortisol, P3, T4 and binding proteins CBG, TBG, albumine~ T8PA were investigated in 14 normal adult males and 24 adult male patients with acute phase parasitlc diseases : amebiasls~ schistosomiasis filariasis~ hydatid0sis, malaria. Each individual was submitted to 3-7 hr blood punctions at fixed hours (04.00, 07.00, 10.00 am ; 02.00, 06.00, 12.00 pm) during 48 hr. The techniques employed were specific radioimmunoassay for total hormones~ rocket immunoelectrophores~s for proteins, equilibrium dialysis for CBG activitzes (H. ZOUAGHI etal. Clin Chem 1984 in the Dress) and free hormones. Data obtained revealed evidence of infradian (~ 48 hr for malaria) and czrcadian (~ 24 hr for other parasitic eases) rhythms of each the hormones (with the exception to total TS) and proteins (with the exception to TBPA) as validated by eosinor method (0.012 ng/ml,Pl>lOOpg/ml,E2l >O.bng/ml,T).This reduction of the variability can be referred to the increased use of direct kits and to the selection,~mong these,of the ones most consistent with the"fraditional"extractire 3M-RIA.In fact the within kit variability was found significantly lower for direct assays(20-256V3 as compared with 32-34CUM fo~ extractive methods) imoreover the agreement of results from direct assays(y) with results from"reference"extractive 3M-RIAs{x),was found to be either acceptable over the entire EQCS period for E2 and T(E2,pg/ml:y=l.lx+4;T,ng/mi: y=l.4x-O.O4),or to change,for P,from an initial unacceptable overestimation(P, 1st pe~iod,ng/ml:y=l.3×+0.6,>lO0% overestimation of foliicular values) to a virtual ¢oincidence(P,2nd period,ng/ml: y=l,Ogx-O.OG). Therapeutic drug monitoring may essenNaIly assist to reach the dosage of amlnoglycoside antibiotics and vancomyeln supposed to be required. We investigated the clinical usefulness of monltoNng the plasma level of these drugs. In the plasma of 804 patients aged 2 to 94 years who were ~n surgical, medical, or paediatNc intensive care, the peak concentration and, if possible, also the trough level after intravenous administration at gentamicln, tobramycln, netiImlcin, amlkacln, or vancomycin was determlned by radioimmunoassay. Doubleantibody methods and 1-125 labeled antigens were used. Gentamycin was measured in 612 analyses, tobramycln in 4593, netHmicln in 2472, amikaeln in480, and vancomycln ~n 627 analyses. In all patients, plasma 62-mlcroglobulln was estimated by radioimmunoassay in order to obtain information about the renal function which may be impaired durlng such antibiotic therapy in a very high dosage. Therapeutic monitoring of these amlnoglycoside antibiotlcs end concomitant determination of 69-mieroglobulln (or creatinine) in plasma helped to kSep thepbsma level of these antibiotics wlthinor near the therapeutic range. This procedure prevented the dosage of these antibiotics from being too low and therefore ineffective or from being too high and thus leading toadverse effects such as deterioration of renal function. In conclusion, the radlolmmunoassay ofamlnoglycoslde antibiotics (gentamlcln, tobramycln, netilmlciiN amlkacln) or vancoraycin in plasma may considerably aid to assess their appropriate dosage and, if necessary, to rapidly adjust it to the assumed requirement. Part of the beneficial effect of hyposensitization seems to be due to development of "blocking antibodies" which are mainly of lEG class ; so, monitoring the level of these antibodies in desensitized patients is recommended. We have developed a liquid phase radioi~ununoassay using different labeled antigens (honey bee venom, yelow jacket venom, cocksfoot grass pollen). Crude antigens were labeled with iodine 125 by the standard chloramlne T method. In order to study the major antigenic components, we have fractionned crude labeled antigens by chromatography on an ACA 54 column and tested each fraction for its immun~reactivity. The standard procedure was carried out as follows : to 100ul of each dilution of serum, I00~I of crude 1251-antigen or isolated 125I-component were added. After an incubation step at 25=C, separation of the bound and free fractions was achieved rapidly by the use of a second antibody in combination with polyethylene glycol (PEG). The results are expressed as a "binding index" in reference to a strongly positive IgG serum. gy inhibition experiments the several assays were demonstrated to be specific for the respective IgG antibodies. The isotypic specificity was confirmed by performing absorption experiments with an anti-lgE. The within assay coefficients of variation ranged from 2 p.cent to 6 p.cent, and between assay coefficients from 5 to 15 p.cent. This assay was applied to the determination of specific IgG in the sere of patients submitted to hymenoptera venom or grass pollen immunotherapy. We have found a good correlation between crude extracts and isolated antigens. In hymenoptera venoms therapy we followed the IgG levels as a function of cumulative doses of venom injected to the patients ; a maximum was observed for about 400~g of venom. This assay may be a useful tool to evaluate the efficiency of different hyposensitization regimens (crude~ partially purified or modified antigens, various dose or schedule). 99m-Te-DMSA is accumulated for a major part in the proximal tubular cells of the renal cortex. It is assumed generally that this site is reached by extraction of the tracer out of the peritubular capillary blood into the tubular cell. Some data however suggest, that handling of 99m-Tc-DMSA in the kidney takes place by glomerular filtration and subsequent reabsorption in the proximal tubular cell. The following observations support this hypothesis. Clearance studies (CI) of 99m-Tc-DMSA were performed simultaneously with 123-l-iothalamate C1 using a continuous infusion technique. Two groups of patients were studied: (l) a group (C) of 30 patients with different renal disorders, with a wide range of glomerslar filtration rate (GFR) (5-160 ml.min-I/].73 m 2) and without tubular disfunction, as measured by lysozyme CI, and (2) a group of 20 patients with proximal tubulopathy (PT) of different origin, also with a wide range of GFR and with elevated relative CI of ]ysozyme. The relative CI of 99m-Tc-DMSA, expressed as CI 99m-Tc-DMSA/ GFR was in group C 6-13% and in the PT patients ]4-35%. Plotting of U.V (urinary excretion of 99m-Tc-DMSA) versus filtered load results in a lize that passes through the origin. The slope of this line is significantly steeper in the PT group (29%) in comparlso~ with the C group (9%), In case of acutely deminished glomerular filtration pressure, as can be encountered during treatment with captopril the kidney uptake of 99m-Te-DMSA was temporarily absent, as was the 99m-Tc-DTPA uptake, while 123-Ihippurate excretion persisted. These findings are compatible with glomerufar filtration and subsequent tubular reabsorption as the normal pathway of 99m-Tc-DMSA in the kidney. Departments of Nuclear Medicine, Pediatrics and Internal Medicine, University Hospital, Groningen, The Netherlands. An association between nephroptcsis (NP) add hypertension hgs been proposed by several studies. A Ooldnlatt mednmnam has been supposed to affect mobile kidney blood flow by slzetdniNg of the renal artery. Aim of the study was to asses~ the posturgl c~es Of l~oal bl~ flow in hyp~J~ceDsives with ~. TO I~SA uptake test %as performed in 16 essential hyperbsnsives (EH) with ~ and 9 EH ~vitt~at KD. Kidney IN~zes in 128 x 128 nmtmix (60") in the prone position were acquired by a lerze field of view ~smamer-e~zcmpater system, t,~ hours after the dose (2 mCi) injection. Each patient was studied twice, at a few d~ys' interval, respectively afte~ ~ hours of standing and t~o hours of supine position. By selection of isolevel ROts and bac~d subtraction kidney counts were obtained sad kidney to kidney uptake ratio (UR) was detsru/ned. Compared to supine values a decr~ase of UR after standing v~s observed in the h~ pbs (i.00 + .19 vs .72 + .14 t=5.ON, p<.OO]; mobile vs controlateral kidney) but not in the non NP pta (i.02 + .17 VS 1.04 _+ .16; right vs left kidney), A significant co~relation was observed between UR after standing and an index of k/dney rotation in pte ~th NP (r .87; p<.Ol). The results indicate an orThoststic reduction of ~nilatoral kidney function in f~ertensive pts with ~ which could be due to renal blood flow modifications. ~e degree of kidney rotation appears to be an important deter~/n~nt of this posture-dep=~ndent effect. The correlation between renographic parameters and bloadpressure ~esponses on percutaneous transluminal angioplasty (PTA) in 72 patients with unilateral renal artery stenosis (URAS) were studied. All patients had on angiogram stenosis of more than 50%. According to criteria of the Cooperative study of renovascular hypertension these patients were divided into 3 groups (Gr). Grl: 19 patients, who became nor~1otensive; Gr2:26 patients, who improved and St3:27 patients, who showed no response on PTA. Renography was performed in supine position with large-field qarmnacame£a posteriorly using orthoiodohippurate. Renographic data were collected in 20-see frames and regions of interest were defined with a light-pen. Background areas were chosen below the kidney. From the affected kidney two parameters were obtained. The Relative Hippuran Uptake (RHU), calculated from the integral counts of the second minute and the Difference of Time to Peak (DTP) to the contralateral kidney. DTP <] min was considered to be normal. The results are qiven in the table. Patients with RHU between 35-44% had the best prognosis. Most of the nan responders had RHUvalues >45%; this probably indicates that the stenosis was of no hemodynamic consequence or pathology of the contralateral kidney. In 7 patients with RHU <25% (2 p~tients of Gr3, in whom the stenosis was successfully dilated and in 5 other patients, in whom PTA was not possible) nephrectomy resulted in normalization or improvement of the bloodpressure. We conclude that PJiU is a useful discriminator for the management of URAS-patients, while prolongation of time to peak (DTP ~i min) does not predict the bloodpressure response on PTA. OTP [ One hundred a~d thirty-thr~e consecutive kidneys grafted during the last two years were followed by scintigraphy. P~tterns of prerenal, renal and postrenal complications were rec0~nized. Vascular thrombosis diagnosed by photodeficiency of the transplanted kidney was diagnosed and confirmed in all 10 patients. Fourteen patients havin~ postren~l urological complications (12 leaks and 2 urethral obstructions) were all recognized in the late phase of the scintigraphic study. The differentiation between the known parench~nat0se causes of Knuria was less satisfactory. With scintigraphy, we could diagnose all those cases where the complic&tion was due to causes that required surgical intervention. In the most frequently observed curve patterns of the OIH renogram five easily measurable parameters = time to maximum (TMAX), time from maximum to 75 % of the maximum (175), PMAXIT7D (TMAW75), maximum counts over kidney per pixe] and minute (CRAX), quotient CMAX:TMAX (C/T) and the time to the intersection point of k~dney and bladder curve mere evaluated statistically. Data ~ere extracted from 600 renograms performed in lO0 patients. Results: The normal Functioning tramsplant ~th serum creatinine levels of 2~0230,81 zs called curve type i. Type 2 represents a prolongation of TMAX*T75 and implies an impairment of activity e~ traction and intrarenal transportation. Type 3 is characterized by a prolongation of 175 and points out an isolated excretory disturbance. Creatinine revels range at 3.]731.82 for type 2 and 5. Type 4 outlines severe reduction of OIH uptake in combination with disturbed intrarenal activity transport, lhe other parameters support these findings. CMAX is a measure of volume of functioning renal parenchyms. The desribed patterns of ren~l OIH p~ssage describe the functional state of the kidney. Normal transplants can be distinguished most sensitively from o£gans mith disturbed function, although the changes observed are not specific for a kidney rejection. A rejeetiom can be postulated on the base of an impairment of Fens1 function. This can be achieved by a defined judgement of OIH kinetics. The purpose of our study has been to measure v~2F,GFR and FF by means of clearance determinations.Measurements using 1-131-Hippurate and Yb-169-DT~A have been compared with classical substances as PAH,Iuulin or Polyfructosane.ERPF im hypertensive patients before percutanneous translumiaal angiopl~ sty has been investigated.Follow-up studies of those subjects are bein~ performed for long periods of time. A group of patients after renal transplantation has beea the subject of our znvestigations as well.Validity of cle-a~a~Q &eter~i~a~i@~i~r@l~$i~ te rejection episodes and other postoperative complica~ioms has been studied~' Furthermore effective renal plasma fl0w,glomerular filtratio~ rate azld filtration fraction values have bee= estimated in patients after reconstruction surgery and nephreot0m~. Institute for clizLisal and experimental medicine,l~6 22 P~ague-Z~-l(l~ 9 Vidensk~ 800 ~ Czechoslovakia Ccomputerized assisted Dynamic Reno-Scintigraphy (DRS) has been shown to be an accurate diagnostic procedure in the screening for renovascular hypertensi'on. Aim of our study was to assess the role of DRS in the follew-up of II patients who underwent surgical treatment for renovascular disease. 7 patients had unilateral (2 fibromusco lar and 5 arteriosclerotic) and 4 bilateral (2 fibromuscolar and 2 arteriosclerotic)renal artery stenosis,documented by angiography. DRS was recorded following injection of 0 12 mCi/k9 99m-Tc Glucoheptonate i.v. before and I mos.-3 yrs. after reconstructive vascular surgery(vein or dacron by-pass graft). Serial images and renal time-activity were analyzed according to pre viously established criteria of interpretation. DRS was abnormal in all patients before surgery, 7 patients (2 with bilateral and 5 with unilateral stenosis) became normotensive after surgery; DRS normalized together with blood pressure in thease patients. DRS did not change in 4 patients who did not respond favourably to surgery; all these patients(Z with bilateral and 2 with unilateral stenosis)had arteriosclerotic disease Two of them underwent a new angiography which showed in one case a by-pass occlusion,in the anoter one a renoparenchimal disease. In conclusion DRS seems to reflect well the recovery of renal perfusion after surgery in hypertensive patients with renal artery stenosis. This fact could be useful in the decision to perform more invasive procedures in patients with residual hypertension suspected of having recurrent or or persistent renal artery occlusion. Inst.Semeiotica Mediea,University of Padua,ltaly Rate of glomerular filtration can be approximated conveniently in conjunction to renograms. When used to evaluate an equivocal emptying of the kidney pelvis, simultaneous use of furosemide increases the clinical accuracy of DTPA renoqrams. There are to date no observations to link the renographic characteristics of the kidney to its tubular function. Growing male rabbits with a solitary partially obstructed kidney were used to compare ~e findings of furosemidestimulated J~mTc-DTPA-renograms to the rate of growth and to certain indices of glomerular and tubular function. The presence of a significant obstruction was shown in all animals of the experimental group by an intravenous pyelograms, done 4 weeks after the obstruction had been created. The diuretic DTPA-renograms, performed 4 weeks later, were abnormal in all experimental animals. Dissimilar renographic patterns were recorded in animals with a normal and abnormal rate of weight gain. As compared to the endogenous clearance of creatinine and to the s.c. distal nephton index, similar correlations were noted. We conclude that a standard diuretic renogram provides accurate and detailed information on renal function and on kidney's ability to maintain growth and body homeostasis. We have investigated clinical usefullness of the renoscintigraphy using 99m Te-DTPA in practical urology for 666 times (609 cases) for 2 years. In this report, we would like to present evaluation of i) THE RENAL FUNCTION DURING THE COLIC ATTACK INDUCED BY UROLITHIASIS, ii) POLYCYSTIC KIDNEY, iii) HYDRONEPHROSIS. For the dynamic studies, 10 mCi of 99m Tc-DTPA was injected intravenously as a rapid bolus and sequential images of the kidney were recorded every one second for 25 minutes using a ga~una scintillation camera and on-line microcomputer system. The analysis is performed automatically at night by a microcomputer, i) THE RENAL FUNCTION DURING THE COLIC ATTACK INDUCED BY UROLITHIASIS; This was performed in 14 cases whose affected kiddney was not visualized on intravenous urography. It is suggested that the renal function of the kidney affected with collie attack is temporarily decreased following the decrement of renal blood flow. ii) POLYCYSTIC KIDNEY; This was done for 5 cases. A remarkable feature of the study is non-invasive examination for the kidney comparing IVU, as contrast media is unfavorable for renal function. The study is beneficial not only for diagnosis, but also for follow-up, because of detecting renal morphology and function, simultaneously, iii) HYDRONEPHROSIS; 11 cases were examined. A lot of informations or renal parenchymal change were obtained by the study. It may be concluded that dynamic renoscintigraphy would be the first choice examination in practical urology. An aminoglycoside ~ntibiotlc~gentamicin is labeled with Tc-99mby the reduction of pertechnotate by stanno~ chloride as described previously. Organ distribution of this agent in rats showed a selective renal localization. Administration of Tc-99m-Gentamicin in rabbits confirmed that scintigraphic delineation of kidneys was highly satisfactory. Gentamicin is excreted almost entirely by glemerular filtration.However the radioactivity is retained in the kidney for a long period s~gesting some tubular reabsorption Of this compound followin H glomerulzr filtration. The whole body images of rabbits injected with 2~0 microCi Tc-9£m-Gentamicin were analysed by a gamma oamer~ interfaced with a c~mp~ter. A~eas of interests were generated on each kidney and time activity curve was obtained. The radioactivity concentration in the kidneys as a function of time was described as the sum of two exponentials.The exact renal mechanism for handling radioactivity is presently unknown. However the excretion by glemerular filtration end subsequent tubular re~bsorption could be responsible for the fast and slow components respectively. Furthermore the reasonably longer retention in the kidneys would result in higher target-ethan to baekgro~znd ratios allowing more adequate renal scans,supplemanta~$ to the simultaneous f~mctional studies. Althought the kzdney÷funetion is immature in infants and on the other side is decreasing with increasing age in adults, an adjustment of the kidney clearance for age besides the conventional surface correction is not in common use. Ne compiled more than thausend studies to get a statistical significant relation between age and kidney-clearance. These studies #ere dzvided into three groups:first children belo1~ 2 years (n=71), second childrens and adolescents from 2 to 15 years (n:64o)/58o) and third adults (n:47&o/42&o; age: 16-80 yi). The linear regression of the data in the latter group gave for both sexes a koefficient of correlation of 0.95. The slope of the curves are similar to that of several authors, but surprisingly no great difference between male and female ~as to be detected. The maximal clearance-values have been found in the groups about 8 years, ~here the maturation is finished and the process of aging starts. fhe retrograd prolongation of the regression line calculated for the adults gave a good estimation of clearance-values in the groups between 8 and 16 years. So one can use a linear decrease of clearance starting ~ith 8 years. Discrepancies between maturation age and eaDandar age in children lead to greater deviations than in other groups. In the case of children up to two years the best fit was done by a logarithmic curve. So the total graph of kidney clearance as a function of age consists of three trunks: a logarithmic increase up to t~o years, a slightly increasing linear part from 2 to 8 years in order to get 8 eontinnous connection to the third part, the linear decrease, beginning ~ith 8 years. An inversion and normalisation of this function leads to a correction of individual clearance-values to a standard age. Radiol. Oniversi-t~tsklinik, D-6650 Homburg/Saar, West Germany Since normal values of renal tubular clearance are lacking freguently~we tried to define the normal range of the ortho-iodo-hippurate (OIH) clearance (C). Total renal C was obtained by the OBERHAUSEN technique in conjunction with dynamic renal scintigraphy, using 1-131-01H in adults and 1-123-0IH in children. Data were normalized to 1.73 m 2 surface area. Startirgfrom 1300 clearance studies in adults and 300 ones in children, a normal collective was selected retrospectively by the criteria: a) normal kidney size and morphology as judged by static renal imaging in adults or by IVP in children and b) normal OIH-kinetios of both kidneys. Linear regression analysis was done separately for the age groups 3.5 -15 and 16 -75 years and for both sexes. I) Age 16 -75 years: 243 males and 181 females were considered as normal with respect to renal function. Regression analysis yielded men: C : 670-3.3x (r:-0.38, s:124) (ml/min), women: C = 617-3.3x (r=-0.42, s=I04), x = years, s = standard error. ~he level of signifieanee of the difference in clearance between both sexes was slightly above 5%. 2) Age 3.5 -15 years: 20 cases were considered as normal. Within this small number no significant correlation of C with age was found. The mean (± s) was C = 577 ± 88 ml/min. 3) Plotting all available data from literature as a function of age, our normal values of tubular clearance fit in quite well. After a steep rise between birth and 3 years there seems to be a plateau until maturity. Thereafter tubular clearance declines gradually, the averages of the females being about 10% less than those of men. 4) A normal range can be deduced as C ± 1.65s, C being the regression line or the constant value in the respective groups(90~ confidence interval). C.Bianchi,C.Donadio,G.Tramonti, F.Lorusso,R.guzzardi Many low molecular weight proteins (calcitonin,insulin,glucagon,lysozyme, ~2-microglobulin)are removed from the hlood by the kidney where they accumulate without being eliminated with the urine. The measurement of renal clearance of such molecules needs renal veins catheterization.We are now applying a new noninvasive method for the measurement of the renal clearance of Aprotinin(Ap)~labelied with Tc99m.Ap is a small protein (6500 dalton) which inhibits some proteo lyric enzymes such as trypsin and kalli~ krein.We have already validated Ap-Tcg£m ~sa tracer for reDalsdSntigrap[,s~nce Tt~s ~Ig~ly and s ta~-ly accumulated ~n the kidney with minimal urinary excretion.Renal clearance of Ap(and of other low molecular weight proteins with similar renal handling) can be determined during continuous venous infusion of Ap-Tc99m as: AK Cl= t2 P(t) dt where:~K is the increase of the radioactivity ove~ each kidney measured by external counting and corrected fo~ tissue attenuation, and P is the plasma concentration of Ap-Tcggm. We have studied 5 subjects with normal ~enal function and 1 patient with advanced renal failure. In normal suhjeets renal clearance o£ Ap-Tcggm was about half of the ERR.In the patient with renal failure the values of ~enal clearance of Ap-Tcggm and GFR were similar.This method could give noninvasively the unilateral renal clea ~anee of low molecular weight proteins-handled by the kidney. A renogram without any excretion of OIH into the bladder is up to a factor equal to the integral of the time activity curve of the cc~ti~ent, frc~ which OIH is extracted by the kidneys. An algorythm is proposed, which allowes the mathematical reconstruction of this curve, which is shown to be a two ex~tial function of time. Using Sapirsteins model of OIH kinetics, the transition rates are calculated.simultaneously, the renal clearance is determined using whole body principles. Thus, the vascular vol~me of OIH is given by the quotient of clearance and clearance transition rate. The extravascular volume is calculated from the vascular volume and the intercoRioartmental transition rates. The renograms of 89 patients are evaluated in the a~ i~entior~ ~ara~r. The Vascular volume is found to be 4700 +_ 1100 el. The mean body weight (BW) of these patients was 69 + 11 kg, i.e. the vascular volume is 6,8 % of BW. The extravascular volume is determined to 9100 + 360 ml (13,2 % 5W) the total vol~ae of O11{ distributi~ to 13800 + 3200 (20 % BW). From these results we argue,that O~ is extracted from the whole blood. This assbmptian J/nplies, that the binding of OIH to the red blood cells is a very loose connection, which is solved during the few seconds of red cell passage through the kidneys. The clearance itself was determined, using the pla~ concentration of OIH. Assum//~ a }~c of 45 % and a binding of OIH TO the erythrozyts of 35 %, the distribution volumes are increased to a vascular volume of 5500 ml (8 % BW) , a extra%rascular vo-lura~ of 10700 nil (15,5 % BW) and a total volume of 16200 ~i (23,5 % BW). These values agree wall with the corresponding values of blood volume (7-8 %), intersticial space (16 %) and extra cellular space (22 %) , raentic~ed in the literator. The purpose of this study has been to examine the effect on plasma volume (PV), extracellulaD volume (EOV) and intracellula£ volume (ICV) of conventional HD and hypertonic HD. We have studied I3 patients. Seven were on conventional HD 4h x 3 times-week with a di~lys~te containing Na ISE mEq/l and a osmola£ity of 305 mOsm/kg. The other 6 patients had been since i month before on a stable regimen of hype~tonic HD 3h x 3 tlmes-week with a dialysate of 130 mEq/l Na and osmola#ity 2g5 mOsm/kg with a pe~fusion du£ing the first hour of 342 mEq of CINa. One hour befo#e HD, the spaces Of RIHSA-125I {PV), 35S04Na 2 (ECV initlal) and 3H20 (tot~l water) we#e determined. The pl~sma albumin was assayed hourly, and at the end of the RD the space of 35S04N~ 2 (ECV final) was agsln detevmined. ZCV = Total W~te£ ECV initial. Results: In conventional HD with a weight loss Of 1900+387 g, the PV diminished 14.5~6.4%,the ECV decreased 19.2+6.3% and the ICV increased 1.7+3.3%, showin6 that the weight loss was due to ~he ECV with h~pe#hldFatetlon of the IDV. In hypertonlc HD, with a weight loss o£ 1860+ 668 g, the PV was Deduced in 5.4~4.D%the ECV diminished 10.4+7.4% and the IBV decreased 3.4+ 3.8%, indioatin~ that the weight loss was dueto the ECV in 5a% and to the ICV in 46%. We conclude that the simultaneous isotopic measumement of the body compartments is a useful tool fo~ studying the weight loss duming HD; we have also verified that the use Of hype~tonlc methods allows dehyd~aEion of the intraeellulaF compartment and maintains better the PV duming HD. The problems associated with deconvolution of the renogram are the following: a) a suitable choice of sampling time, b) statistical noise in the data, c) interference of renal and background activities, d) negative values of the calculated renal retention function (RRF). They are still not fully explained and this work is attempting to clarify them using simulated data and matrix algorithm. Statistical noise in the input curve was reduced by fitting data to a sum of exponentials, while in the renogram by using third-order smoothing polynomials (Ba~i6 et al, Phys. Med. Biol. 28:731-738, 1983 ). Since external probes are used for the measurements, "biological" noise consisting of extravascular (£V) and background activities is superimposed on plasma and renal activities. The contribution of the EV to the plasma activity in the cardiac region causes negative values in the RRF and calculated mean transit time (MTT) is underestimated compared to the true one. ~]l points of the RRF, not only the first one, are influenced by the interference of background and renal activities. Still the NTT is not dependent on the background actlvity, c When the minimum transit time is in the range of I-1.5 minutes (it is very often in dinical practice) the sampling interval should be 10-]2 seconds. There is a hyperbolic re]ationship between the coefficient oF variation (CV) oF the MTT and the peak value of the renogram. The error c of the MTT (expressed as a double CV) will be less than I0~ when there are about 5000 counts in the peak. . O 'CnvaLeo, A. Nodal, L. Troncone, R. 9~cc£n£, F. c~. Com~te~Ie~ R~ioisoto~c C{z~£o~ap~( CRC) is the most eommon cause of death i, these patients;heart the impoPt~nce to contPol f~equentI~ the iowep uPinsr x tract function with u~odynamic methods. Since radionuclide essto-urethrog~aphM seems to be a reliable,repetible and sensible method in studying functional "urinary tract diseases,we used this technique to evaluate 15 patients with spinal Lnju~. The bladdem was filled with 99mTe-DTPA and sal! ne with a 14 Oh Foley catheter at 100 cmH20 fil ling pressure,in clinostatism.Filling ~/%d voiding phases were studied with g~mla c~mera on line with a computer.Afte~ the catheter was re moved,the minctional flow W~ studied.Urodyn~m ! variables concerning Fillin~ and voiding pres sure and volumes and voiding flow were studied. ResulEs were comparable with those found with conventional u~od~n~smic techniques.Furthermore a morphological info~ation concerning vesicoumetheral ~efl~ and bladder diverticula was obtained. Radionuclide cisto~et~ography appeared to me--et well diagnostic needs,to be less time con-sum~ng and less distressing for patie~ts than the conventional u~rod~n~amie approach. Cisplatin (CP) is known to be a valuable drug for the treatment of testicular cancer. Preclinical toxicologic studies have predicted the occurence of renal injury and many investigators have found that nephrotoxicity is the dose limiting factor of this drug. Pathologic examinations of the kidneys of patients with CP induced nephrotoxicity have demonstrated extensive tubular necrosis, without extensive glomerular damage. This study was designed to investigate renal damage in 26 patients with testicular cancer receiving 20 mg/m CP daily for 5 days as a part of combination chemotherapy (3 courses included CP), given with vigorous hyperhydration {~00 ml/d). Renal clearance was studied with l-orthoiodohippurate (method of OBER-HAUSEN). 1311-orthoiodohippurate-clearance was not significantly decreased after treatment with CP. Thus, there was no renal damage of tubular function as evidenced by this parameter, contrary to reports by others, who have described CP induced changes in other indices of tubular damage. The present results may be due to the youth of the patients besides vigorous hyperhydration during therapy and possibly for other reasons not yet understood. When the steady-state is achieved during continuous infusion of ~-131 hippuran, ERPF can be caLcuLated by dividing the quantify of the iracer infused per minute by the plasmatic concentration. As ERPF can be determined af any moment as Long as the sieady-sfate is main-Pained, the method can be used in monitor drug ~nduced changes of this parameter. The feasibility and the validity of this method have been evaluated in 17 healthy voLunteers. In aLL cases, the steady-state was achieved Less than 90 minutes after the beginning of the infusion ( .2 uCi of 1-131Hippuran/mI, ImL/min). The reproducibility of the catcutaled ERPF was exceLLent as attested by the stability of the oLasmafic concentratieo 4urin 9 the whole procedure i4 hours). The results were weLL correLa fed with those obtained using the U.V/P method. The effects of the following drugs on ERPF have been invesiigafed : dopamine, subLinguaL isosorbide dinifrate and vasopressin, alone or in combination with nifroprusside. In patients with congestive heart failure, dopamine increased the renal blood flow. The effects of sub-Lingual isosorbide dinifrafe was evaluated in cirrhotic paiients. ERPF was shown to decrease during the first 15 minutes then progressively returned #o the base-Line value, l.V. adminisirafion of vasopressin alone reduced the ERPF which was restored compLeteLy by adding nifroprusside. In conclusion, the dederminaiion of ERPF using continuous infusion of 1-131 hippuran is an easy and reLiabLe method. The diagnosis of tricuspid regurgitation (5~) is difficult and is usually obtained by physical examination, echocardiography and cardiac catheterization. However, theme is no accurate method for cp/antifying TR. RNV provides a relative measurement of left (LV) or right ventricular (HV) volume overload using the so called regurgit~nt index HI = LV stroke counts / RV stroke counts. Because of the right atrial / RV overlap in LAD projection this RI is slightly-higher than 1.0 and averages 1.43 (normal range 0.89 -1.97) in a greater norlnal group studied in our laboratory using a fully automated e~ge detection algorithm for computing HI. In 13 patients (7 men, 6 women) with proven TR preferably following mitral valve replacement (n=10) RI ranged between 0.29 and 0.92 (mean 0.70-0.19) . Only one patient with probably mild TR showed a value for RI = 0.92 slightly higher than the lower limit of normal, thus xesultinq a sensitivity of this approach of 92%. ~n 3 cases examined by RNV recently, TR -in addition to the described method -could be confirmed by documenting the atrium like pattern of the timeactivity curve over a liver ROI. The RI method, however is of limited value in the presence of additional LV regurgitation. The specificity for diaguosing TR from RI is high: in more than 200 consecutive patients without valvelar regurgitation or shunt the range of normal was exceeded in none of the studies (I00%). Among these were also 21 cases with RV enlargement but no RV volume overload. In conclusion, the diagnosis of TR by RNV from a RI below the lower limit is a method with high sensitivity and specificity ~Lnd this approach seems to allow to c~antify TH, although there is no golden standard to proof this. Gated Cardiac Blood Pool 'GBP' scintigraphy was used as a non-invasive technique to distinguish patients with valvular disease from normals and ischaemic heart disease (IHD). Phase analysis has been applied to 54 gated studies. First harmonic Fourier-amplitude ratio of the left and right ventricles was utilised to measures the regurgitation index (RI). In 9 normal control volunteers the regurgitation index from 45 LAO was (1.42 + 0.25 mean + SO, range l.l-l.9). In 27 patients with isehaemic heart disease without valvular insufficiency RI was (1.48+0.25 Mean + SD, range 1.1-1.9). In 19 patients w{th valvuTar heart disease with left ventricular preponderance RI was (3.1 ~ 1.3 Mean ~ SD, range 1.2 -6.3). Initial clinical experience shows that patients with valvular regurgitation were clearly distinguished (P 0.001) from 36 (9 control + 27 IHD) without valvular disease. The group of 27 patients with IHD were net significantly different from the g normal volunteers (P 0.5). In conclusion the Fourier-amplitude ratio derived from the amplitude image appears to provide a reliable means for identifying patients with valvular regurgitation. The temporal relationship of changes in left ventrlcular (LV)[uno~ionto electrocardiographic changes during exercise is unclear. To examine this relationship we have used a non-imaging nuclear probe (NP) (Eios Inc)~ which can detect the rapid alterations of LV function which Occur during exercise. Ten patients (8 male, 2 female) with stable angina and >I mm ST depression on treadmill-testlng underwent symptom-limite@ semi-supine cycle ergometry. The blood-pool was labelled in vivo with Tc-99m 740MEg and beat-to-beat LV time activity was detected by NP and traced continuously by a pen recorder. Background counts were recorded at rest and corrected once during exercise. The LV Ejection Fraction (EF) and the ST segment level 80 msec after the J point were deterT~ined every 30 seconds during exercise. Twenty four normal volunteers were studied using the same protocol. In the ]0 patients the mean gF was 0.54 (range 0.46-0.64) at rest and decreased during exercise in all cases by a mean of 0.17 (0.08-0.25). By aontrast~ EF increased in all normals by >0.05. All patients developed >I mm ST segment depression, but in 9 of i0 EF fell by >0.05 before the appearance of I ~ ST depression. Thus, in most patients with stable angina, impail~ent of LV systolic function was detected earlier than the electrocardiographic changes associated with exertional myocardial ischaemia. Chronic renal failure (CRF) frequently affects cardiac function through various secondary disorders such as anemia, hypertension, uremia and fluid overload. Hemodialysis partially reverses these effects. This study aimed at quantifying such effects on central hemodynamics, using the method of minimal transit times (MTTs), which were shown to express the ratio volume/flow. 22 patients (P) with CRF were examined before and within 30 min after closure of the arteriovenous fistula used for hemcdialysis. -10 P were examined before and 12 P after dialysis. Cardiac and segmental central MTTs were measured as previously described, using a multiprobe camera the head of which was placed in AP-view of the chest. Each P had regular clinical examinations including blood pressure, BUN, creatinin and hemoglobin. Number of dialyses per individual P ranged from 30 to 293. 41P without renal or cardiovascular disease served as controls. Of the unselected P with CRF, 40-45 % had prolonged cardiac MTTs prior to dialysis which were very significantly reduced following dialysis. Of P dialysed ]ess than iO0 times only 20 % had prolonged MTTs, versus 50 % of P with more than 100 dialyses. -7D % of P with hypertension, but only 45 % of P without hypertension, showed increased prolongation of MTTs by closure of the shunt. -Pulmonary MTTs remained normal in all groups. -There was no correlation between MTTs and BUN or creatinin. For optimum volume substitution therapy in cardiac risk patients during and after greater surgery the estimation of the patients individual LV pressurevolume characteristics (Frank Starling curve) is essential. Because of the complex and non-linear pressure-volume relationship the measurement of the LV filling pressure (PCWP) is not sufficient. Therefore, in this study PCWP was gradually increased up to 15-18 mm Hg by stepwise infusion of 5% albumine in I0 cardiac risk patients in 6 times 200 ml increments. At each volume loading level, PCWP along with the radionuclide equilibrium ejection fraction (iF) and thermodilutlon stroke volume index (SVI) were determined, and the LV enddiastolic volume index (EDVI) was calculated by EDVI=SVI/EF. Unexpectedly, there was a relative uniform preloadvolume-pressure response in all but one patient, with an only moderate but non-significant increase of the EOV[ and SVI and a significant rise of PCWP, despite an always normal EF. The mean values presented as follows: (PCWSg) (maY}m) ~m~Y~) ~) 7.2+2.4 46.1+6.9 66.4+ 16.6 71+11 9.772.5 48.8+4.9 68.4+]3.6 73712 11.5+2.9 50,5+4.9 71,6 + 15,8 73712 12.2 ~ 3.5 50,6 ± 4.7 71.6 ~ 12.0 72 + 10 ]4.8 ± 3.8 51.7 +_ 6.9 70.8 +_ 14.0 74 + ] l I5.3 + 4.0 50.9 + 7.7 73.9 + 16.5 70 + 12 In conclusion, in the vast majority of this patient group studied the pressure-volume characteristics has shifted to the right on the Frank Starling curve, where volume loading leads to immediate increase of the LV filling pressure without significant increase in EDVI or SVI, while the EF Being normal and remaining relatively stable. In this typ of patients, perioperative volume substitution should be performed with caution. Radionuclide ventriculography along with right heart catheterization allows to dlscover this typ of patients preoperatively. Nuclear Medicine Division, University of aim, DWgOO Ulm, Germany MEASURgMENT OF THE BRBATHING RELATED HEART FUNCTION. W. Waters, W. Neeb, U. Buschsieweke, U. Wellner As the functions of heart and lungs are closely related, a method for the measurement of the breathing related heart function is established. Method ECG triggered multigated equilibrium radionuclide ventriculographies are acquired during different phases of the breathing cycle determined by a second trigger derived from the endinspiratory or the endexpiratory point. In normal persons (n=10) the ejection fraction (EF) , the diastolic and the systolic count rates of the left ventricle were not significantly different between the inspiratory and the expiratory phase of the breathing cycle. The right ventricular EF fell from 66m9 % during inspiration to 62~9~ during expiration (n.s.). The diastolic count rates did not change. The systolic count rates were significantly different (p=5%) between inspiration (43~15%) and expiration (60._12%)-(percent of the inspiratory diastolic count rate). Considerable differences of cardiac performance between the inspiratory and the expiratory phase of the breathing cycle were found in pathological states of the heart and the lungs. Conclusion New insights into the pathophysiology of the functional unit of heart and lungs can be achieved by the described method. Its value as a diagnostic tool will be estimated by further investigations. Thallium 201(20iTI) myocardial imaging has been successfully used since 1976 :[or the diagnosis of right ventricle hypertrophy (RVH) or right ventricle pressure overloading (RVPO) due to pulmonary arterial hypertension (PAH), but important series of chronic obstructive pulmonary disease (COPD) patients were rarely investigated by this method. We ~-6~s decided to study the diagnostic value o:[ -TI myocardial scintigraphy, by comparing the results with hemodynamic findings, in 73 patients with chronic respiratory diseases, mostly COPD (n=59). Patients were investigated at rest in the sitting position. Myocardial sci#~graphy started 10 minutes a:[ter I.V. injection of "TI (2Z~pCi/Kg) and the four projection study was interpreted by 2 independent observers. RV activity was graded from O (no activity) to 3 (activity that o:[ the left ventricle). Patients were divided into 3 groups according to the level of pulmonary artery mean pressure (P-A-P) : P-A-I~20 mmHg (no PAH) = group 1, n=28 ; P~ ranging :iron 2i to 30 mmHg (mild or moderate PAH) = group II, n=25 ; PA--A'~3g mmHg (marked PAH) = group III, n=20.RV was visualized in 16 patients in group Ill (80%) and in I# patients in group II (56%). For ali the pat~ts with PAH (groups lI and II1) the sensitivity ol T] imaging for the diagnosis o:[ RVPO was ol 67%, higher than that of EGG (53%) and comparable to that o:[ echocardiography (65%). For patients with only mil~01to moderate PAH (group I1), the sensitivity ol TI, even if moderate (56%) was better than that of ECG (36%) or echo (50%). A high RV activity (grade 3) was observed in only ¢ patients (2 in group II, 2 in group III). The speci:[icity o:[ this method was of 75% (RV was visualized in 7 out o:[ 28 patients in group I), as compared to 72% ~ echo and 96% for EGG. The results suggest that ITI myocardial imaging could be of interest for the non-invasive diagnosis of RVPO in COPD patients, but the senshivity of the method is rather weak when PAH is mild (PAP up to 30 mmHg). Centre R&gional de Lutte eontre le Cancer PAUL STRAUSS -67085 STRASBOURG CEDEX. Left ventricular angiocardiography, roentgenkymography, eehocardicgraphy and nuclear cardiologieal examinations /Ti-201 myocardial scintigraphy and EGG-gated equilibrium cardiac blood pool scintigraphy/ were performed in 58 patients after myocardial infarction or with isehemie heart disease. Left ventricular ~neurysm was proved in 31 cases, diffuse myocardial lesion in 4 cases, other disturbances of the motility of the chamber wall in 25 patients. The results of the left ventricular angiosardiography, eshecardlography and nuslear earddologieal examinations were in each ease analysed jointly by 3 cbservers. In the detection cf aneurysms, the weakest performance was given by kymography. With echocardicgraphy the accuracy of diagnosis was good, but it was not possible in all cases to take satisfactory exposures /emphysema, obesity/. With nuclear cardio~ogieal examinations most of the left ventricular aneurisms could be diagnosed /sensitivity: 85 %, specificity: 90 %/. The comparative studies indicate that the non-invasive nuclear cardiolcgical methods provide effective help in the recog~itlon of post-infarct aneurysms. Biomedical EnEineerin E in the Kerckhoff-Clinic of the MYOCAPCDIAL iO patients (Gr I) with chest pain, positive ECG stress-test (occurence of more than I mm ST depression during stress and/or pacing)~but normal coronaro-ventriculography, without methylergometrin-induced spasm were studled.None had an history of myocardial infarction, or valvular disease. Just after IV injection of 74-111MEq ~-123I-HDA, 120 images were collected over 30 mr, in basal state, on anterior projection,using a gamma-camera equipped with an all purpose-parallel collimator. Waiting for 30 mn, patients received then the same dose and a new data was collected under pacing during 30 mr. After blood background substraction (using 555 MBq SA-99mTc),tw0 myocardial clearance curves of m-1231-HDA were generated and elimination half-tlme (TI/2) determined. Were also studied: stress-thallium scintigraphy (TI) and rest-pacing coronary lactate metabolism. Results were compared to those of 13 patients with dilated or obstructed ear-~iomyopathy (Gr 2) and normal subjects (Gr 3). In Gr i, T1 was normal in all cases but 2 and TI/2 decreased significantly under pacing (37.6±16.1 mn to 31.2d7.0 mn, p i0 months). We conclude : I) The incidence of I.S.D. increases as the interval between donations decreases 2) The incidence of I.S.D. is higher in the young groups than i~ old groups, 3) S.F. is a parameter of great value to prevent iron defieie~ cy anemia in blood donor. Two cc,mercial inwnunoradicmetric assays, one using monoclonal antibodies to spleen ferritin ~/t selected to react with both liver and spleen ferritin, the other using polyclonal antibodies tO liver ferritin, were used to measure ferriti~ content in serb~ and figured blood elements in 20 normal subjects. For sert~n and erythrocyte ferritin a highly significant linear correlation between the results of both assays was found (r>0.95) . For granulocytes end mononuclear cells, hcwever, lower linear correlation coefficients w~re observed (r>0.8). According to the type of sample different reqression slopes were observe~ in sertwa the results for both assays did not differ significantly (slope 1.08) ; in red cells there was a marked decrease in response of the monoclonal antibody (MA) assay oampared to the polyclonal (PA) assay (slope 0.27). These ~sults indicate the nonrecognition of part of the erythrocyte ferritin by the ~lq. It has been shown that red blood cells contain two immunological different ferritins. The difference observed between both assays could be explained by amonospecificity of the MA for tile spleen-type,which is also the most abundant ferritin type in the sezl~n. An additional ar~ent for this is that the median erythrocyte ferritin content found in the present study with the MA is nearly identical to the values obtained by other authors using polyclonsl antiboOties specific for basic ferritin. Ferritin Contents in granulocytes and memonuclear cells were significantly lower with MA. This could be the result of a different cellular isoferritin oclnposition with respect to sertwa and erythrocytes or of a different oanposition ~nonocytes,l~mphocytes) for the mononuclear cell samples. These findings indicate that both assays are equivalent for the assay of seru~ ferritin, but not for figured blood elements. A high specificity of the MA for basic liver type ferritin is also suggested. Bloodtransfusion Center Antwerp end University Hospital Antwerp, wilrijkstraat 8-10, B2520 Edegem, BelgiL~. THE QUALITY CONTROL OF ~ITLMIN B-12 SCHILLING TEST VERSUS SERUM g-12. M. Antar The accepted standard procedures in a clinical setting for the assessment of vitamin B-12 absorption is Schilling's test and serum vitamin B-12. The latter is in equilibrium with tissue stores and ~s usually a reliable index of the total body vitamin content. We encountered a relatively large number of patients with a normal Schilling (>8% dose), and low serum B-12 (below 180 pg/ml). Therefore, we investigated different aspects of the quality control of both tests and the incidence of these discordant results in a V.A. patient population for three years. Th~ average age was 65 + ]0.5 years old. Serum B-12 was determined using a "R"-protein ~nhibitor in 1,605 consecutive patients. Of these, 116 patients hod standard Schilling test, without istrinslc factor, using purified Ce-57 Vitamin B-I2 capsules. The incidence of T'false" negative for Schilling tests was approximately 28%, (32/115). Mean serum vitamin 8-18 of this group was low; 135.8 + 29.9 pg/ml, (N: 200-950 pg/ml), and Schilling 24-hour urinary radioactivity as % dose was normal, 16.8 + 5.7. Mean plasma radioactivity at 8 hours was 1.03 ± 0.38 (N: >D.5%/liter). In contrast to serum B-12, mean serum Folate was mormal, 7.9 Z 4.8 ng/ml, (N: 1.4-13.7). Megaloblastie anemia was present in 60% of the patients. Cirrhosis or ethanol abuse was the major common factor present (in two-thirds of the patients). Other conditions which may have contributed to this discrepancy are, partial gastrectomy, vagotomy, cimetidine and dilgntin therapy. These findings show that the "false" negative results of the standard Schilling test in the population studied, is relatively high. A migration test for leukocytes under blood agar was developed, leukocytes moved quite a distance under anaerobic Blood Agar Base (blood agar), a Gibco product. This medium contains various possible ehemo attraetants and the observed cell motility is built up by random migration and directional migration to the theme attractants in the agar medium. Migration on stained and coloured plates was visualized by projection with a profile projec-tor~ making the use of a light microscope superfluous, A migratioo index was defined. Reproducibility was good enough, to allow paired comparisons with leukocytes subjected to different treatments. Dose response effects of three eomplexing agents on leukocyte migration were assessed. Those eomplexing agents were oxine (ox), %ropolone (trop) and 2-mercaptopyridinei-oxide (marc) all known as potent cell labelling agents. It appeared that mere seriously affected cell motility in all concentrations tested. ~rop bad the best properties with regard to toxic effects. Concentrations up to 70 ~q/ml labelling preparation (lO ~g/ml ultimate incubation mixture) did not significantly affect leukocyte motility. Ox did not affect leukocyte motility up to a concentration of 25 pg/ml labelling preparation (5 pg/ml ultimate preparation). Results imply that mere should not be the appropriate cell labelling agent to be used in abscess localization studies. Byk-Nallinckrodt CIL B.V. The kinetics and in rive distribution of lll-Inlabelled autologous platelets were studied in 25 healthy subjects. Using the multiple hit model, platelet mean life time (~uT) averaged 185h, platelet in vivo recovery (IVR) 56%, and platelet turnover 55437 pl./pi/24h, simultaneous stUdies were carried out in 7 subjects with identical platelet suspensions labelled with ill-In and 51-Cr, respectively. The III-In-MLT v/as slightly shorter and III-In-IVR slightly nigher than those of the 51-Cr-platelets, and the lll-In-platelet survival curves tended to be slightly more curvilinear than the 51-Cr-curves. This may be ascribed to a slight elution in vivo of lll-In-activity fran the platelets, judged by t/qe results of c(luparative studies of pla~bound activity in the saraples of ill-In-platelets prior to their injection and in blood samples obtained at intervals following injection. ScintiDra~nic studies: The splenic activity rose in a monoexponential n~qner, reacning equilibriuln ~ithin 30 rain. Followi~g an initial peak at around 10 rain post injection, the hepatic aCtivity showed a rapid initial decline followed by a slower decrease lasting roughly one hour in most subjects, ald accc~oarded by opposite changes in circulating platelet-bound activity. Using a scn~iquantitative approach, the quantities of platelets sequestrated and destructed in the spleen, liver add bone marrow were estimated. Platelet sequestration predc[ninantly occurred in the spleen (a~ound 85%), the regaining prestz~ably being sequestrated in the liver. The contributions to platslet destruction amounted to roughly 40% (spleen), 25% (liver) , and 35% (bone r~arrow), however, with considerable interindividual variation. The bone marrow component may have bee/1 slightly Overestimated as we found scintigraphic signs of slight platelet destruction in the lungs. Imaging techniques in medicine require fast transfer of images and written information to the clinician in order to allow immediate decision making. This task is markedly alleviated by use of instant film material without need of darkroom, chemical solutions, time consuming processing procedures or special processing machines which require space and service. There are several facilities to have the clinical information on transparency film or paper film at all film sizes. Colour film provides special advantages to show the clinician convincing results, however, up to now colour was only seldom used to stress the significance of circumscribed abnormalities in scintiscans. Furthermore colour is a facility to co-ordinate heterogenous information providing a basic structure which is easily seized, so that the conduction of written and pictorial information to the reader is guided by use of colour (identical colour for ROI, curve, numerical results, written text). 35 mm film (colour, black/white) to be used in everyday standard camera types and processed within 2 min is the last step for a complete concept, as it facilitates the minification of images for long-time documentation or medical training {slides) having the data always in the department without the possibility of data misuse during extern film development. The limited availability and high cost of 1123-IMP is a major drawback in the study of the early events in cerebral ischaemia.201Ti-DDC was developed by us as a highly lipophilic agent with considerable brain uptake. It can be easily prepared at low cost on a daily basis. We here report on a comparative study between 20~fl DDC and II23-IMP in rabbits and dogs. After injection of 0.5 mCi in rabbits, whole-body timeactivity curves were obtained employing a gamma camera and computers for brain, lung, liver, kidneys and background. The brain uptake of TI201-DDC occurred more instantaneously compared to II23-IMP, and the level of activity remained moxe stable. No lung retention was observed for TI201-DDC. Three minutes after injection the following values were obtained. As part of our program to evaluate techniques for radiolabelling of antibodies, we have used human IgG as a model system to study the des feroxamine (DF) coupling reaction using glutaraldehyde or carbodiimide at various concentrations. Diethylenetriaminepentaacetic acid (DTPA) was conjugated to IgG via the carboxycarbonyl mixed-anhydride or the carbodiimide reaction. The IgG-DF and IgG BTPA conjugates have been labelled with Ga-67 and In-111 with a labelling efficiency of 60-96% with good reproducibility and stability. Radiochemical purity was assayed by sephacril S-300, sephadex-G50 or EPLC using a TSK 30OSW column with similar results. Labelling efficiency in relation with storage time of the conjugate was analysed by sephadex-G50 and paper chromatography using Whatman #I and 85% methanol: with yields ranging from 96-34% after 1-30 days storage at 4°C. The electrophorectic mobility was determined by SDS polyacrylamide gel electrophoresis. The conjugate was found to possess similar electrophoretic mobility as native IgG. As an extension of this work, we have conjugated the rat IgOr b MoAb MI0/76 (which is specific for the chemically induced Mc 24 rat sarcoma) with DF at a M:R 1:40. The plasma clearance in normal rats 48 hours after injection was 4 hours versus 18-24 hours for the I-]25 labelledM10~6. Localization of the antibody into the Mc24 tumour in syngeneic Lister hooded rats is being evaluated and compared with a similar antibody (11/160) with specificity for the rat sarcome HSNt.c. The rapid blood clearance of this rat MoAb precludes high concentrations in the tumour and enables imaging within a shorter time after injection. Changing the antiserum specificity of a RIA system is known to be a potential cause of con-cern~ by possibly altering the response of calibrators, samples and controls. Most often, patient samples and commercial controls react in a similar manner to this changed specificity. However, this needs not necessarily to be the case. We report two antiserum changes which were accompanied by sometimes dramatic alterations in the apparent analyte content of several control preparations, while the findings for patient serum samples were unaffected. The assays involved were: a direct estradiol assay (EIR, W~renlingen, Switzerland) and a TSH assay (Amersham International, UK). The differences in apparent analyte content, compared to the previous titration, ranged from 85 to 179% for the estradiol kit and from 27 to 123% for the TSH kit. In both cases, no significant difference could be demonstrated regarding the assays of patient serum samples. It is interesting to note that, in the case of TSH, the antiserum change affected not only commercial internal quality control (QC) preparations, but also samples from external QC programs, such as the Wellcome control program and the Belgian official external QC scheme. The assay resul~s being pooled in such programs, important biases are to be anticipated. The reported discrepancies were ascribed to the fact that, in control preparations, analytes may not be present in the native form, but also as a metabolite, a subunit, a degradation product or even as a non-human analog. This difference in composition as compared to true, not degradated human sere must be regarded as a major cause of a different hehaviour of these control preparations with respect to the change in antiserum specificity. Therefore it is obvious that neither the kit manufacturer, nor the performing laboratory can be considered to be responsible for discrepant results generated in this way in both internal and external QC schemes. Dept. of Nuclear Medicine, Antwerp University Hospiaal, B2520 Edegem-Belgium. Antibodies to different types of collagens are useful tools for studies on connective tissues. describe a solid-phase radioi~Enunoassay using z51-protein A which can be applied to immunochemical analysis of antisera against purified collagens raised in various species. Collagens (human and bovine) were extracted from skin (type I), cartilage (types II, I~2~3~, XI-X 7) and placenta (types III, IV, V), and controled, after purification, by aminoacid analysis and polyacrylamide-gDg gel electrophoresis. Antisera to collagens of different types were raised in rabbits, goats, guinea pigs and mouses. P2otein A was labeled with iodine 125 by the chloramine T method. The test is performed in polystyrene microplates with removable wells. The influences of the pH and the concentration of the coating solution on the adsorption yield of collagen were evaluated. We determinated the effect of varying the amount of collagen used for the coating on the sensitivity of the assay. Optimal conditions were achieved with 25 ~g of collagen in 200 ~I phosphate buffer pH 7,6. After incubation of antiserum overnight at + 4°C in coated wells antigen-antibody complexes were detected by 25p-protein A overnight at + 4°C. Rabbit, guinea pig and even mouse antisera could he assayed directly ; to ensure an accurate detection of goat antibodies, an additional step of incubation with a rabbit anti-goat IgG serum before adding the labeled protein A was required. The assay was reproducible : the within assay coefficient of variation ranged from 3,5 to 7,5 p. cent and the between assay coefficient of variation from I0~9 to 18,5 p. cent. We prepared plates coated with 9 different types of collagens. The specificity of each system was demonstrated by inhibition experiments. This assay is a suitable method for measuring the titer and the cross-reactions of different batches of antibodies to collagens. A competitive binding receptor radioassay for 1,25(0H) 2 vitamin D, with sufficient sensitivity for studying maternal and foetal (cord serum) levels, from a few millilitres of serum has been developed. High specific activity tritiated tracer 1,25(0H) 2 D and standard or serum e~tract are allowed to react with intestinal receptor in a total volume of 150 U1 10% ethano]ic 0.05 M phosphate buffer, pH 7.4. The reaction is terminated by adding 40% polyethylene glycol, the receptor-ligand complex spun down and the supernatant counted. The standard curve is plotted as free/total counts vs. total assay concentration. The CVs were 11% and 15% (intra-, interassay). Using high pressure liquid chromatography with ~H-tracers for 25-OH D and 24,25(0N) 2 D a total of 21 cord and 82 pregnancy sere were analysed. Foetal 1,25(0H) 2 D levels (mean 77, range 23-159 pmol/l) were less than normal adult levels (105, 30-150+, p< 0.05) and pregnancy levels were higher than both these (169, 39-291, p< 0.01, and < 0.001). Diabetic mothers had lower 1,25(OH)2D levels than all other mothers taken together (p < 0.01). At cord 1,25(0H) 2 D levels > 110 pmol/l the babies were larger (p < 0.02). Cord 1,25(OH) 2 D levels correlated positively with 25-0H D levels (p< 0.05). These patterns were not seen in pregnancy serum but at higher 25-0H D and 24,25(OH) 2 D levels babies were larger (p< 0.01 to < 0.04). 25-0H D correlated with 24,25(OH)2D (p< 0.001) and the regression of the former on the latter in pregnancy serum showed that 25-OH D was 18 nmol/] when 24,25 (OH)2 D had fallen to zero (p < 0.001). This suggests preferential use by the foetus of the latter, perhaps in the maturing skeleton. Specific radioimmunoassays have permitted accurate measurement of variations in plasma hormonal levels over the 24-h-cycle. Free or unbound cortisol in plasma is the biologically active form at the tissue and cellular level. It moves freely out of the bloodstream into tissue cells where it acts. As there are not binding-proteins, the determination of cortisol levels in saliva seems to offer a number of significant advantages as compared with plasma or serum measurements, and radieimmunoassay is the technique of choice. Direct parallel determinations of cortisol in human saliva and blood were investigated by a solid phase RIA. The samples (102 male volunteers) were taken at 05.30, i0.00, 15.30 and 22.00 h. Circadian patterns of cortisol in saliva and in blood were identical. On the other hand, after stimulation of saliva secretion (here: sucking a lemon) the saliva level of cortisol decreased and was statistically different from controls. These findings suggest that cortisol can be measured directly from saliva and accurately reflects serum unbound cortisol. The method is simple and accurate, but only when saliva is collected without secretory stimulation which may produce an alteration of cortisol concentration. Dysbaric osteonecrosis is a chronic cc~plication which occurs with deep sea divers and individuals working under cc[~pressed air. Typical sites of bone necrosis include the ht~neral and fersDral beads, shaft of tibia and fibdia. 29 adult n~le divers (age25-58), were i~vestigated. A detailed x-ray survey and whole body bone scan (Tc-99m-NDP) was used to iccalise the disease. X-rays were reported by an exit rne~nber of the Medical Research Co~cil Decompression Sickness Panel and by an expert physician in Nuclear F~dicibe in a blibd fashion. X-ray examinations are insufficient and contrast arthrography time and work consuming to diagnose meniscus injuries of knees in orthope= dioso 43 patients were controlled by arthrotomy to determine specificity and ~eneitivity of Gamma Kemera-made 9mTc-EDP knee-scans.How to separate method local meniscus injuries from diffuse eynovitis? Anterior picture of knees showed "point like"accumulation between tibial and femoral condyles in typical cases of meniscus laesions. The lateral image showed "strip like" activity accumulation at the identical place.Pictures were analysed without knoledge of other clinical results.The reality of scans was controlled after arthrotomy.There were 21 true positive and t4 true negative,5 false positive and 3 false negative eases. The sensitivity of method was87~and the specificity 73_%. The 5 false positive scans were caused by "corpus liberum","plica eynovialis"and circumscript synovitia.The 3 false negative scans were caused by previous immobilization of patients.The noninvaeive method is useful to discover and docume~ meniscus injuries of knees and is very helpful before invasiv arthroseopy to show "dysfunctional areas" of Joint. Angular deformities of the extremities in children following partial premature closure of the growth plate are well known. The deformities depend on the position of an osseus bridge or fibrous scar which forms between the epiphysis and metaphysis. Several surgical procedures incl~diDg resection of the osseus bridge have been described, however delineation of the site of fusion is difficult to define. The eormnonest site of growth plate arrest is the distal femoral or proximal tibial growth plate. A new technique using the bone scan has been developed which accurately defines the area and position of these ossens bridges or scars. Two hours after injection of technetium 99m methylene diphosphonate apex views of the affected distal femoral growth plate were performed. The knee was flexed into its smallest angle. Using a pinhole collimator the gamma camera was angled at 90 ~ to the affected growth plate plane. The image was collected onto computer and analysed by: (i) regions of interest over segments of the growth plate to calculate the relative area of total growth plate affected; (it) generating histograms; (iii) thresholding or performing isocontours to accentuate abnor~&l areas. The growth plate is normally uniformly increased when compared to the normal shaft of the bone. With a uniformity variation of less than 15%, fusion across the plate appears as an area of diminished uptake. The apex view gives a unique functional map of the gro~cth plate such that abnormal areas are displayed, and the site, size and position of osseus fusion obtained. The technique has the potential for determining the metabolic activity of the growth plate before and after surgery. Serial studies will allow assessment of regeneration of the plate and reformation of new osseus bridges or fibrous scars. TI-201-scintigraphy has been reported to be useful in the detection of metastases from thyroid carcinoma after thyroidectomy. To evalmate the reliability of this procedure T1-201 total body scintigraphy was performed in 218 patients,after total thyroidectomy for histologically proven thyroid carcinoma. Results were correlated with 1-131 scintigraphy and tumormarker levels(Tbg or Calcitonin/CEA). TI-201 scintigraphy correctly demonstrated tumor localizations in 16 of 19 patients with 1-131positive metastases. In 4 cases the TI-201-scintigram and in 4 other cases the 1-131-scintigram showed more localizations. T]-201 total body scintigraphy was negative in 150 patients with no evidence of disease,however 9 of these patients had elevated tumormarker levels. In 26 patients TI-201 total body scintigraphy revealed metastases which did not concentrate 1-131. In 16 of these patients only tumormarkers indicated disease. M~tastases have sofar been confirmed in 16 patients. 7 of 13 patients with medullary thyroid carcinoma had elevated levels of Calcitonin and/or CEA. In 5 of these patients metastases were localized by means of TI-2Ol-scintigraphy, Comparison of Tl-201, 1-131 and tumormarkers showed that none of these parameters alone is completely reliable in follow up of thyroid carcinoma. However the combination of a negative TI-201-scintigram with a negative tumormarker was never associated with disease in our series. It is concluded that: I) TI-2Ol total body scintigraphy is a useful parameter in postoperative thyroid carcinoma, especially when a discrepancy of the other parameters exists; 2) TI-2Ol-scintigraphy is of particular use in medullary thyroid carcinoma; 3) in follow up of patients who are unsuspected of disease after suceesful therapy for thyroid carcinoma one can rely on T1-201 total body scintigraphy when tumormarker levels are low or undetectable. In papillary and follicular carcinoma of the thyroid gland scintigraphy with 13]-I and thyreoglohulin (TG) measurements in plasma are unique tools for the detection of recurrence or metastases. Recently the uptake of 20J-T1 in thyroid cancer has been reported as a complementary scintigraphic technique. He did a comparative study of these three diagnostic tests (seintigraphy with 13]-I, measurement of TG and scintigraphy with 201-TI) (n=71) in 60 patients with papillary or follicular carcinoma. This was a selected group of patients with suspicion of recurrence or metastases (elevated TG or suspicious mass) after total thyroidectomy and 131-I ablation therapy. Total body scintigraphy using ]31-I was performed 2 weeks after T-3 withdrawal. 20J-T1 scintlgraphy was done (one day before 131-I scintigraphy) ~0-50 min. after i.v. injection of 30-70 MEg 20[-TICI. TG was measured using a radioin~uunoassay (upper limit of normal : 60 ng/ml off T-3). A total of 31 positive 20]-TI scans were obtained. In ]7 of these 31 cases the 13]-I scan was positive ~nd PG levels varied from ]]0 to 9600 ng/ml (mean 3000 ng/ml). In 14 of the 3] positive 2OI-TI scans a negative 131-I scan was found; in these cases TG varied from 35 to 1000 ng/ml (mean 310 ng/ml). In the patients with a negative 20]-TI scan (n=40), five 131-1 scans were positive. TG in this group ranged from 30-380 ng/ml (mean 110 ng/ml). In 13 patients the finding of a positive 20]-TI scan was crucial for the localization of the metastases. We conclude that 201-TI seintigraphy cannot replace scanning with ]3]-1, but it can be of great help in case of a high TG level or other indication of recurrence when scintigraphy with 13]-1 is negative or cannot be performed because of the risk of temporary T-3 withdrawal. After new tumour markers in serum had been introduced the question arose whether also patients with turnouts of the urinary tract would benefit from this development. We assessed the clinical value of a series of tumour markers in the serum of 79 patients who had a carcinoma of the kidney, prostatic gland, or testis. During follow-up of 18 patients with renal carcinoma, 30 with prostatic carcinoma, and 31 with testicular carcinoma, the serum level of ferritin, prolactin, 13-HCG, CEA, CA 12-5, CA 19-9, TPA, AFP, and, as a supplement in the patients with prostatic carcinoma, prostatic acid phosphatase was measured by radiolmmunoassay. Among the patients who suffered from renal carcinoma, serum ferdtin had increased in 16, prolactin in 8, TPA in 7, CA 12-5 in 3, AFP in 2, and CEA in one whereas prolactin was reduced in 2 patients. In the patients with prostatic carcinoma, serum TPA was elevated in 22, prolactln in 21, ferritin in 16, CEA in I0, AFP and 8-HCG each in one man; serum prolactin had decreased in one patient. Among the patients who had testlcular carcinoma, serum prolactin was raTsed in all men, TPA and ferritin each in 24, B-HCG in 16, CEA in 13, and AFP in 9. Serum CA 19-9 had not risen in any patient. The follow-up of the patients demonstrated that the most su~tabJe tumour markers in serum were ferritin, prolactln, and TPA in patients with renal carcinoma and those with prostatic carcinoma whereas in addition CEA and AFP should be determined ~n patients with cancer of the testis. In conclusion, radiolmmunoassay of lumour markers in serum of patients with renal, prostatic, or testicu[ar carcinoma promotes cancer control in order to assist in the early detection of turnout growth, recurrence, or metastases. The distribution of 1-123 labelled isopropyl amphetamine has been shown to reflect cerebral perfusion. This study set out to compare amphetamine images with those from X-ray CT and NMR for a range of cerebral pathologies. To date 27 studies have been carried out; 15 on patients suspected of having vascular disease, 8 on patients with tumours and 4 on normal subjects. All radionuclide studies were carried out with a rotating tomographic camera and a high sensitivity tomographic scanner. Patients also had an NMR CT study and an X-ray CT scan within 24 hours of the radionuclide investigation. The 8 patients with tumours had, in addition, a conventional 99m-To pertechnetate brain scan. All 8 tumour patients showed no uptake of amphetamine over the tumour site and in two of these the 99m-To pertechnetate study was negative. In patients with old infarcts, of greater than 2 months duration there was good correlation with the X-ray and NMR images. More recent infarcts appear larger than on the other modalities probably due to the amphetamine study showing the surrounding isehaemic areas. Reproducibility of the technique has also been studied, in particular the effect of different physiological stimuli at the time of injection. Comparative studies have shown that SPECT 123-I-AMPHETAMINE IAMP) imaging of the brain show perfusion defects more distinctly than X-Ray Computer Tomography. The aim of our study was to establish the clinical value of this method in the follow-up of patients wi~h cerebro-vascular disease after therapy. Patients: 74 with cerebro-vascular disease, 21'before and after surgery. Method: 5 mCi 123-I-AMP i,v. SPECT was started after 3o min. using a rotating gammacamer (G.E. 4ooTl. Results: The tomographie clices show a marked 123-I-AMP accumulation in the grey watter and lower activity in the white matter. Activity in the cerebellum could also be detected. There are typicalpatterns of perfusion defects which correlate to the occluded cerebral arteries. The lesions were usually more pronounced in SPBCT then in CT. Besides showing areas of major infarction seen on CT scaus, SPECT is able to detect the areas of borderline perfusion between different vascular territories. The defects correlated closely to the neurological symptoms. After surgical intervention a better accumulation in the corresponding hemisphere could be registered in the majority of cases. Patients with extra-intra-craniel bypass show local hyperaemia at the site of the anastomosis. We conclude that 123-I-AMP gPECT of the brain is a promising noninvasive method for the follow-up and therapy control of patients with cerebro-vascular disease. The clinical NPH features usually comprise a disorder of stance and gait, urinary urgency and incontinence and intellectual disorders, abulia or psychomotor retardation. In the past years many authors have attempted to define reliable criteria to select patients who might benefit from CSF shunting, Cisternography, showing persistent ventricular reflux, impaired conductance outflow of C.S.F. and, CT demonstrating enlarged ventricles and CSF migration through the wails, were unreliable criteria to predict outcome after shunting. We applied 1-123 IMP tomoscintigraphy to 17 patients (10 females mean age: 70.1, 7 males mean age: 6#.5) with suspected NPH. 6 to 7 mCi of 1-123 IMP (CIS France) were injected intravenously (eyes closed and ears plugged) before and after CSF lumbar withdrawal (10 to 60 co). Imaging was performed with a rotating gamma camera (CGR) from 20 to 60 rain after injection. Like MATHEW and GRUB8, our results demonstrated that frontal and frontoparietal regions were affected to a greater extent along with a decrease in basal ganglia activity. After CSF drainage, cortical perfusion was improved on g patients with a good correlation (7/g) with clinical criteria (mental disorders assessed by psychometric tests, gait disturbance and urinary incontinence); the correlation was poor with CT findings except perlventricutar lueency. 9 patients were shunted, one recently, 7 patients upon S were cEnicaliy improved after CSF permanent shunting, had a concomittent improvement of cortical perfusion after CSE drainage test and was a better criterion than clinical appreciation of this drainage, Assessment of regional perfusion with 1-123 IMP before and after CSF drainage may provide objective information concerning the suitability of NPH patients for CSF shunting. In about one third of TIA or stroke patients the angiography is normal or shows only slight atherosclerotic lesions. Nevertheless, in these patients the long term prognosis is as bad as for patients with carotid disease. Scintigraphy with Indium-t11 labeled platelets proved to be an effective method in detecting mural thrombi in the neck vessels, which may be the source of arterio-arterial emboli. We performed platelet scintigraphy in 42 patients (29 TIA, 13 completed stroke) whose angiography was normal or showed only dif-fuz~ atherosclercsis without ev!gence of occlusion, stenosis or ulceration. In 29 of the 42 patients (69%) our results showed pathological platelet accumulations on the side clinically affected. After other possible causes of cerebral ischemia e.g. cardiac emboli or hypetensive crisis had been excluded, the pathological platelet deposits proved to be the cause of the attacks. 46 examinations in 43 subjects, 20 of them M and 23 F a2ed from 3 to 82 years have been performed. 8 presented fever of unknown origin,19 suspected intraabdominal abscess (15 of which had bad recent abdominal surgery),12 suspected brain abscess,7 patients were referred with other loeali zations. ~/BC were separated by sedimentation addin 2 to SO ml of venous peripheral blood, in a sterile tube, 5 ml of AiD and 1,2 ml of 2% methyleellulose in saline.The leuEoeyte-rich-pla sma was transferred in a second tube and centrifuged st i00 G for 5'.The supernatant was removed and the pellet resuspended in 1 ml of PBS. An average count of 9,41 x 104 WBC/mm S was obtained in the final suspension and the number of administred WBC was nec~rly 0,85 x 108, with approximately 87~ neutrophils. Final suspension-WBC/venous peripheral blood-WBC ~atio was 10,05 (12,22 for the neutrophilic 2ranulocytes). The average number of platelets and RBC was respectively 3,58 x I08 and S,32 x 108(less than 4 RBC per WBC).To this suspension 750 pCi-l,2 mCi (27,75 -44,40 MBq) of Inlll-0xin e (gmersham) were added. Granulocyte labeling efficiency rangod from 52 to 100% (average 77%).Images were obtained at 6 ~d 24 hours after administration of Postoperative fever is common after abdominal operations, often associated with clinical signs of intraabdominal or wound abscess. Some patients require additional surgery for abscess drainage. Others recover without surgical intervention as their inflammatory process, presumably of non-abscess nature, is cured by antibiotics mr resolves spontaneously. The objective of this study was to find out whether z111n granulocyte scintigraphy could distinguish between these two patient groups, Methods. ZZZln-oxinate autologous granulocytes, purified by means of density gradient centrifugation were used and scans obtained 3-24 hours after their reinjection. 22 patients with fever and clinical signs of abscess were investigated with SPECT and/or planar views. Results. 14 patients had to be operated for abscess drainage. In 13 of these, the scan correctly outlined the abscess before surgery. In one patient, the scan was negative, operation was performed because ultrasonography had shown a Douglas abscess. At operation, however, a sterile hematoma was found. 8 patients recovered without surgery. In 7 of these, scan was negative. One revealed a slight accumulation in the upper left part of the abdomen after splenectomy. This might have been a small abscess or an accessory spleen. Conclusion. zZIIn granulocyte scintigraphy thus ~eliabl~epicts postoperative intraabdominal abscesses that need to be operated. However, due to the comparably high radiation dose from zZiIn, repeated examinations should be avoided, especially on young patients. In addition, iZZln is presently available at our hospital only once a week and this limits its usefulness in acute situations, such as in the diagnosis of abscesses. Department of Surgery, Karolinska Hospital, P.O. Box 60500, S-I04 Ol STOCKHOLM Leucocytes labelled with lll-lndium have been used to visualize inflammatory lesions in ulcerative colitis (UC) and in Crohn's disease (CD). The aim of this study was to compare findings by scintigraphy, radiology and endoscopy in patients with slightly or moderately active disease. Material: UC: Twelve patients (median age 36 yrs ~weYe studied. All were non-febrile, 8 recieved sulphasalazine,none steroids. CD: Fifteen patients (median age 46 yrs.F/M:7P3Ywere studied. A11 were non-febrile, two recieved prednisolone 5 mg/daily, 8 sulphasalazine. Methods: Leucocytes were labelled with lll-ln-Oxine (0.15-0.67 mCi) and given i.v. Scintigrams were obtained 3 and 24 hrs. p.i. Double contrast x-ray studies of the colon and small intestine were done after 2 and 14 days respectively. Colonoscopy with multiple biopsy was done after 4 days. Results: Active lesions were found in 24 of 27 patients. Location and extension of the lesions were in some cases masked of the intreluminal activity on scintigrams ~4 hrs. p.i. Excretion in the stools were 2.4-25.8% of administered activity, Compared with scintigraphy a corresponding extension and location was found with colonoscopy. In 4 patients with UC x-ray of the colon was normal but scintigraphy and colonoscopy showed active inflammation. Conclusion: Scintigraphy after injection of Ill-In labelled leucocytes is an atraumatic method for visualization of inflammatory lesions in UC and CD. The location and extension of inflammatory lesions can be visualized and the method appears more sensitive than conventional x-ray studies. Computed transmission tomogrsphy (CT) has greatly facilitated the diagnosis and localization of brain abscesses and has thus contributed to an improved prognosis in dlis severe condition. The differential diagnosis between brain tumor and brain abscess is, however, not seldom difficult. Scintigraphy with indium labelled autologous leucocytes has proven to be a valuable technique for the demonstration of intraabdominal abscesses. This stwdywas undertaken to evaluate whether this technique could also be used to diagnose brain abscesses and to differentiate between tumor and abscess. Technique. Following cell separation, the leucocytes were incubated with indium-Ill oxinate (10-20 ~mq] and then reinjected intravenously. Detection was performed in 3=5 projections after 24 and 48 hours using a gamma camera with medium energy collimator. Results. 16 patients have so far been examined -all with clinical and CT findings compatible wzth both brain tumor and brain abscess. In 4/5 patients with the final diagnosis of brain abscess leucocyte scintigraphydemonstratedmarkedly increased activity corresponding to the lesion detected by CT -in the fourth patient a small central lesion could not be demonstrated. This patient i~ad, however, been successfully treated with antibiotics for 8 days. In I0/II patients with the final diagnosis of a malignant brain tumor, leucocyte scintigraphy was negative, in one patient with a large superficial malignant tumor with extensive meningeal engagement, activity corresponding to the ttuaor was, however, seen. This gives an overall accuracy of 14/16 (88%). Leucocyte scintigraphy thus has an important role in the differential diagnosis between brain tumor and brain abscess. The kinetics of 111-In oxine labelled platelets were studied in thrombopenic purpura. The advantage of 111-1n over 51-Cr is that it can be used in autotransfusien however severe the thrombocytopenia may be and that sites of platelet destruction can be visualized with a scintillation camera peaked for 170 and 245 key with a 20 % window. Normal autologeus 111-Ie labelled platelet distribution was tested in 6 volunteer controls. 180 cases of thrombopenic purpura (176 idiopathic thrombopenic purpuras ; 4 congenital thrombocytopenias) were investigated. Fourteen patients underwent a double exploration : one with autologous 111-In labelled platelets and the other with donor 51-Cr labelled platelets. The patients entered into this study were investigated at least three weeks after any treatment. The exploration protocol included counting the radioactivity of blood samples for platelet survival. A scintillation camera interfaced with an image processing system was used to study early in viva platelet distribution and late hepato-splenie sequestration. Scintigraphic imaging techniques give a precise description of the early kinetics of hepatosplenic pooling. This is useful when making a differential diagnosis between thrombopenic purpura and hypersplenism. They also enable the relative importance of the sites of destruction to be assessed : in this study purely splenic uptake : 85 % of cases, purely hepatic uptake : 5 Z of cases, mixed hepato-splenic uptake : 10 % of cases. The method is useful in confirming the diagnosis of idiopathic thrombopenic purpure, in quantifying the degree of platelet destruction and in indicating whether the patient is eligible for surgery. The kinetics of autologous lll-In-labelled platelets (pl.) were studied in 50 patients with thromhocytopenia (idiopathic thrombocytopenic purpura (ITP) : 27 patients; congestive splenomegaly (CS) accc~qganying chronic hepatic disease: 18 patients; splenomegaly frcm other causes: 5 patients) . In the ITP group, pl. mea~_ life thee (MLT) was considerably shortened (x = 45 h) , in viva recovery (IVR) was slightly lowered (x = 45%) , and pl. turnover slightly increased (~ = 66700 pl./pl/24h), however, all 3 parametres showing considerable interindividual variation. In the CS group, the mean values were: MLT: 124h; IVR: 31%; pl. turnover: 44477 pl./pl/24h. No correlation was found between MLT and pl. concentration in blood in any of the two groups. Platelet turnover was positively correlated to the pl. concentration in the spler~smegaly group; these two parametres did not correlate in the ITP group, suggesting subnormal tbrc~nbopoiesis in both groups. The pl. concentration was positively correlated to IVR in both groups. This was expected in the splenc~egaly group; in the ITP group it may reflect increased vulnerability of platelets frcrn patients severely affected, resulting in pro{nature removal of labelled platelets from the circulation upon reinjection. Alternatively, it may reflect ir~reased platelet pooling in I~P, contributing to throalbocytopenia. This is supported by a positive correlation between IVR and spleen size in both groups. Scintigraphic studies: In the splenomegaly group, pl. seq~/estration and destruction occurred almost exclusively in the spleen. The ITP patients could be divided into 2 groups; one (n = 15) erdzibited a predc~ninantly splenic platelet destruction, the other showed signs of a ccmbined splenic-hepatic or hepatic pl. destruction. In both groups (ITP and CS) scintigraphic stmdies of the chest revealed signs of pl. destruction in the home rq~rrow as well. Department of Nuclear Medicine, Ode~se University Hospital, DK-5000 Odense C, Denmark. A new high Density Avalanche Chamber positron camera is now in operation at CERN. It will replace the prototype camera that is in routine use at Geneva Hospital for high resolution (2m m) three-dimensional imaging. The camera is larger (30 x 30 cm 2) and is 16 times more sensitive owing to the use of multiple gammaray converters. Spatial resolution remains at 2-3 ~a and cime resolution 20 as. The construction and performance of this camera will be described and some imaging applications presented. A special purpose gamma camera collimator with holes which converge in the plane of rotation of the camera has been used together with an IGB 4OOA camera and STAR computer system i~ order to achieve high resolution siugle photon emission computed tomography (SPECT). The collimator has been used for high resolution thyroid imaging of patients with pyramidal nodes, enabling the anatomical origin of the nodes to be identified. The resolution of the system has been measured using a line source of activity in a uniformly attenuating medium. A detailed quantitation of the variation in the shape and widths of the llne spread function has been made for six positions of the line source in the field of view and for three radii of revolution of the camera. At the centre of the field of view the line spread function is circular; elsewhere it is elliptical. The exact shape of the ellipse depends on the position in the field of view; in general the major axis of the ellipse is parallel with the line joining the line source to the axis of rotation of the camera. The resolution of the same rotating gamma camera system with both a high resolution parallel hole collimator and a low energy general purpose parallel hole collimator has been measured under identical sets of conditions and the improvement with the use of a converging collimator demonstrated. Typically a full width at half maximum in water of Igmm has been achieved with the converging collimator compared with 18m~, for the high resolution collimator with a radius of rotation of 25cm. A three fold improvement of sensitivity at this distance was also achieved. Reconstruction software is a specially modified convolution and back projection algorithm in which the shape of the frequency filter and the frequency cutoff may be varied. ~e algorithm has been implemented using the IGE software feature "programmability". In conclusion the experimental conditions for optimum high resolution SPECT have been achieved. The objectives of this study were to determine the optimum conditions for improving images of the liver and spleen obtained by single photon emission computed tomography (SPECT). The aim was to enhance the contrast of cold liver lesions whilst avoiding the simultaneous generation of unacceptable mottle in the normal liver. BPECT tomograms were obtained using an IGE 400T gamma camera with STAR computer system. Contrast was defined as the ratio of the minimum pixel value in a reconstructed cold spot to the mean of pixel values in surrounding normal liver. Mottle was defined as the r.m.s, error divided by the mean of pixel values in normal liver. SPECT tomograms of a London liver phantom containing a 25m~Q diameter cold spot were processed by several filtering techniques including maximum entropy deconvolution, homonmrphie deconvolution, Phillips filtering and inverse filtering. The image processing algorithms were developed inhouse within the ICE software facility "programmability". The changes in tumour or cold spot contrast and normal liver mottle were determined for each technique and for a range of the free parameters available. The unprocessed tomograms had a tumour contrast of 39% and mottle of 14%, Optimum processing increased the contrast by a factor of greater than x2 whilst mottle increased by only xi.1. Choosing other less favourable conditions contrast enhancement by x2.5 was possihle but with x2 (unacceptable) increase in mottle. In conclusion contrast in SPECT liver tomograms can be greatly enhanced under carefully controlled conditions and with defined end points for evaluation. A total of 100 patients in whom a firm, final clinical diagnosis had been made from surgery post mortem or clinical and biochemical findings, are included in the trial involving brain, liver and bone studies. The ability of the SPECT system to detect pathology which was absent, equivocal or evident on conventional scintigraphy is evaluated and the sensitivity and specificity of the system calculated. An ROC analysis of the comparative results is presented for 4 observers, 2 of whom had no experience in evaluating SPECT images. The results show conclusively that training and experience in Handling SPECT data enhance true positive detection rate and that SPECT is superior to conventional scintigraphy in the detection of pathology in brain, liver and bone. Major obstacles in quantitative evaluations using SPECT are accurate attenuation correction and proper handling of scattered radiation. These problems could be treated separately or together. A technique for subtraction of scattered radiation before correcting for attenuation has been developed, The method is based on "deconvolurico" of scatter events from the measured profile data. The functions defining the distribution of scattered radiation were determined from measurements with a line source in a water phantom. The iterative atteeuation correction technique used in this study is based on comparison of measured profile data and calculated profile data, These are obtained from summation #ixel by pixel along a "ray" in the reconstructed image, Each pixel value is weighted according to an estimated effect of attenuation. An advantage using this kind of attenuation correction is that information concerning attenuation properties of the object obtained from transmission measurements could be used in the calculations. If no separate scatter correction is applied the build-up of scattered radiation may be taken into account ie the estimation of the effects of attenuation by modifying the attenuation function. Computer simulations and phantom measurements, with 80 mm long cylindrical sources in a 300 mm diameter cylindrical water phantom, using the techniques described above indicate that the activity concentration could be determined to within ±10% independant of the size and position of the "source" within the body. Single Photon Emission Computed Tomography (SPECT) in children suffers from relatively poor photon statistics due to the lower radiopharmaceutical dose when compared with adults. Consequently, we have made a major effort to improve the resultant temographic images. We compared the effect that different enhancements had on the basic reconstruction, The baseline study was a reconstruction with an internal filter appropriate to the planar image's photon density. The first enhancement was to three dimensionally filter plaear images prior to reconstructing with an intermal "high resolution" filter. The second was to apply three dimensional filter to the images which were reconstructed with an internal "high resolution" filter. The filtration an~ reconstruction were performed on Both MOS-A , A and GE Star computers. The results showed that planar images Which were of poor photon flux produced much better reconstructions when pro-filtered, whereas the difference was not nearly so d~amatic with high photon flux studies. Therefore, we recommend routine pre-reconstruction three dimensional filtering on all SPECT studies, especially those of poor photon flux. In fact in some very low photon flux 24 hour CSF, Thallium and Gallium studies, it was only possible to interpret those images when prefiltered first. The design and initial performance characteristics of the original dynamic phantom for quality control checks of camera/ computer systems are presented. The phantom consists of two rubber balloons filled with Tc-99m solution. The balloons intended to simulate heart chambersare filled and emptied periodically by means of two pistons that are operated by specially shaped cam discs situated on the common shaft driven by a motor. An ECG trigger pulse simalating the R wave in cardiac studies is generated for each rotation at a position equivalent to enddiastole. Both balloons are placed in e water bath in a glass vessel containing Te-99m to provide simulate¢} body background activity. The phase delay in filliDg of balloons can be adjusted by the mutual turning the cam discs through an angle desired. Knowing the true characteristics of the phantom arrangement, e.g. left ventricular ejection fraction, end-diastolic Volume~ end-systollc volume, cardiac output, systolic emptying and diastolic filling rate etc., it is possible to compare these values against those observed and computed. Experience with this dynamic phantom has dem@mstrated that it is a very valuable tool in testing overall gated acquisition system performance, including hardware, and computer programs used for the analysis of cardiac radiomuclids data. Examples of the use of the phantom are given end its advantages in comparison with other ones described in literature are discussed. and I "basenear" was imaged in air with 360°and 180°revolution.After back-projection(Ham/ning-filter) in transverse slices and reorientation to sagittal,frontal and oblique planes, som~ small blurring was noticed in the 18C-data.All 3 defects could easily identified by reduction in count activity to 25-30% in the defects containing no activity. In a water tank with scatter the 360 data showed without attenuation correction a decrease of activity from the apex to the base to 55-60%.In the 180°data attenuation caused a activity decrease to 40-50% in the base compared to the apex. Contrast however was better in the 180°data compared to the 360°-data:~he apexnear defect showed in the 180-data a decrease of activity to 25-35% and in the 360°data to 35-45%,the midventricular defect showed in the 180 ° data a diminution to 30-35% vers 50-55% in the 360 data,the basenear defect was lowered to 35-45% in-~e 180°data and to 55-60% in hhe 360°d~ta.Attenuation correction for the 360 data did not change v the contrast,but lowered the activity loss in the base to 80%. In a preliminary study of 12 pat.with either 9osterior-posterobasal ischemia or infarction,we could clearl X demonstrate the sufficiency of the 180~rotation (RAO-LPO)without attenuation correction in TL-2OI-SPECT. We conclude,that myocardial TL-2OI-SPECT can be eva~uated with certain precaution in the 18C--rotation offering more contrast. Dep The Siemen's orbiter 3700S single-photon emission computed tomography (SPECT) system can acquire tomographic images in both step-andshoot and continuous-rotation modes. We have compared these modes in scanning patients and phantoms. For a study requiring 360 ° rotation, a brain scan was selected. After a 20-mCi injection of Tc-99m gl~coheptonate, a continuousrotation study was followed by a step-and-shoot study. The same number of counts were recorded at 2 ° intervals for 180 projections. For the study requiring 180 ° of rotation, a cardiac exam was selected. After a 2-mOi intravenous injection of thallium-201, continuous rotation through 180 ° was compared to a subsequent study in the step-and-shoot mode. For both modes the same number of counts were recqrded at 20 intervals for 90 projections. The resulting images were the same for both scan modes, but total scanning time was longer with step-and-shoot than with continuous rotation (27 mid vs. 18 for 180 views in 360 ° and 22 mfn vs. 18 for 90 views in 180°). This difference between the modes was due to the time interval required each time the camera head was moved from one angle to another for the step-and-shoot mode. This time difference is directly related to the number of views collected or the total number of angles sampled. In conclusion, the continuous-rotation mode is preferable due to shorter patient imaging time for SPECT study without degrading the image quality. Summation of data from multiple continuous-rotations would be preferable when it is uncertain how long a patient can remain immohile for the exami~atio~ or when distribution of the radiopharmaeeutical being investigated would change during a slower rotation. imaging has been utilized in diagnostic radiology for years. Poor resolution has, however, inhibited its use in nuclear medicine. In this work we developed a system for stereoscopic nuclear medical imaging. The system is based on the use of a high resolution gamma camera (GE 400 A/T), which has an FWHM resolution of 4.2 mm with a high resolution collimator. Two slightly differing views were collected to a Gamma-t1 computer with 500 kcounts each. The images were displayed side by side on the dual display buffer of the system, and further photographed on an ordinary slide. The slide was viewed with a cheap stereoscopic viewer (Asahi Pentax). For testing the system phantoms with active rods in air were imaged with an angular separation of ±g and ±10 degrees between the views. Better depth perception was obtalned with the ±5 degree separation, which corresponds to a viewing distance of 40 cm and minification of the order of 2.5. We conclude that the system gives additional information to planar scintigrams with a simple procedure in cases where small size increases of activity are present, especially in bone scans of the head, thoracic and pelvic region. Lack of divergence in the images due to a parallel hole collimator slightly distorts the stereoscopic effect. Respiration induced organ motions during NMR data acquisition reduce the contrast of images. Therefore the recording of spin echo sequences is done while the patients hold their breath. The period of stopped respiration has to be detected for controlling data acquisition. Because the patients cannot hold their breath longer than a few seconds only some of the 128 image projections are recorded every nonbreathing period. This paper deals with trigger pulse generation derived from different temperatures of inspired and expired ai~ flow. g small thermistor located inside a breathing mask is used to measure the changing temperature. This sensor type provided with twisted and shielded leads and RF filter circuits has proved to pick up little RF and magnetic field gradient switching noise in NMH environment. Transitions between respiration periods are identified by sudden gradient changes of the measured temperature-time function. Different temperature gradients at transition time are used in the device to distinguisch between normal and non-breathing periods. If respiration is stopped the NMR imbuing procedure is released via ECG trigger channel for an appropriate number of sequences recordings. When imaging the beating heart at the non-breathing period the standard ECG equipment output line is connected via the device to the imaging system ECG channel as long as respiration is stopped. Then each ECG triter pulse initiates the sequence of one image projection recording. NMR imbues generated with and without respiration motion illustrate the improvement of contrast. Medizinische Hochschule Hannover, Abteilung Nuklearmesstechnik, D-30OO Hannover Bl, FRG A514 THE ~o-~THED TO DETERMINE TI RELAXATION TIMES R. Bauer, 0. Lauer, U. Bauer TI and T2 relaxation times are inherent characteristics of different tissue. It is anticipated that some pathologies and malignancies can be differentiated by their respective relaxation times. A prerequisite to discriminate tissue alterations is an exact and reproducible measurement of TI times. Data published in literature differ widely even when measured at the same field strength. This uncertainty might be due to I) the statistical error which is potentiated in calculating TI times when large numbers are subtracted £r0m each ether 2) the spin lattice relaxation time being not monoexponential but more complex and 3) hence different pulse sequences and repetition times tR result in unequal weighting of the respective TI times, producing deviating 'mean' TI times. Applying inversion echo sequences and 2-dimensional FT reeonstruetion~ we determined the inversion delay ~ at which the resonance signal was zero. From r o , TI was calculated iteratively according to T1i = ~o/in(2-exp(-t/T1i-1)(2-exp(-~e/T1i-1))) with re being the echo delay and t = t~-E=-rm the relaxation period. The '~-method' is insensitive to statistical errors and results in reproducible Imean TI times' when tissue with complex relaxation characteristics is investigated. Measurements were performed at the Hausst~n Clinic, using a resistive system (Teslacon M Technicare) at 0.15 T. Some TI times (ms) are given below (mean ~ SD, n=10): TlOf water protons in the liver of rats was measured with a pulsed NMR spectrometer operating at 20 Mgz. Concentrations of paramagnehic trace elements Cu,Fe,Mn were determined by means of neutron activation analysis. Lowering of the Mn-Concentration in the liver by a chemically induced cirrhosis (thioacetamide,TAA) showed an increase of T 1 , while a small increase of Mn-concentration in the liver (after injection of a hepatobiliary Mn complex) shortens T 1 . Changes in liver Cu had only a minor influence on T I . Representation of T 1 and Mn~oncentration of all animals (controls, Mn injected, TAA treated) in a diagram demonstrated a correlation, which suggests a dependence of liver-T I from Mn-concentration. Stimulation of liver growth and enzyme activity by phenobarbital, however, showed a correlation between Tland Mn concentration which differs from that described above. Because a 30-40 fold change in paramagnetism of Mn by complexing the metal with different ligands can be demonstrated in vitro, it may be assumed, that a different degree of complex formation: of Mn with enzymes in the liver (mainly dehydrogenases of the micosoma] fraction) will also affect T 1 in the liver. A dynamic phantom was constructed in order to evaluate and measure @/qe absorbed dose in the thyroid trap efter pertechnetate thyroid up-takes. This phantom consists of a polyethylene cylinder (thyroidal pool) connected to tworese~oirs of saline and sunk in a "neck mimicking cylinder". ImCi Tc-99m was injected into the top reservoir (blood circulation) and a 2-compartment model employed in order to find the rate of change of Tc-99m uptake both in euthyroidal or hyperthyroidal situations ~nd be used with our experimental system. LiP thermoluminescent dosimeters (TLD) placed on the "thyroid cylinder" to measure the "organ" dose as well as on the neck phantom to measure the "skin" dose in a dynamic procedure mimicking thyroid's pertechnetate uptake. By TLD dosimeters we also measured the skin dose on normal volunteers and hyper thyroidal patients. Comparison of our dynamic phantom and in vivo measurements, with theoretically calculated doses,shows a good approximation. A deviation of values less than 5% for euthyroids and 10% for hyperhytoids was found. Wa ceucluded that we can rely on the values of skin doses measured by TLD to estimate thyroid's dose. TLD skin dose measurements could be easy and reliable method for the dose estimation of many organs. Nuclear Med.gect.,Dep.of Radiology, Araeteion Hosp., Univ. of Athens, 76, Vas. Sophias, Athens, Greece. Measurements of body radioactivity as required by radiation protection regulations in Austria have been performed routinely in radiation workers using a shadow shield whole body counter at our department. Spectrum analysis includes identification of the contaminants and quantification of their activity. In order to increase the accuracy and to speed up the processing of the measurements a commercially available spectrum analysis program has been adapted and evaluated with regard to the special requirements of whole body counting. These are the need for frequent and rapid calibration of the system and the correction for an unusually large fraction of scatter radiation. For energy calibration point sources with at least 6 different gamma energies are necessary in order to give the accuracy necessary for, identifieation purposes. Efficiency calibrations have been performed using calibrated radioactive solutions in an antropomorphic phantom. The background subtraction algorithm showed to be reliable even in the presence of complex gamma spectra to give reasonably accurate results (max. 30% deviation from true activity). Our results indicate that fully automated assessment of radioactivity in the human body using computerized spectrum processing can be performed with an accuracy sufficient for radiation protection purposes. The results are available immediately after the measurement, which is an additional big advantage in the case of a radiation accident. The optimum pulse height analyser window settings for a study depend upon the relative number of scattered and unscattered gamma-rays present within the window. A mathematical model was, therefore, developed to calculate the amount of scattered radiation produced at each stage in the imaging process. Three sources of scatter were considered. The first was scatter produced by the patient's tissue. This was modelled by considering a point source of radioactivity at the centre of a sphere of tissue. Cross-sections derived from the Kleln-Nishina dlfferential crosssection were used to calculate the amount of scatter as a function of energy. The second source of scatter was assumed to be in the collimator. The relative intensity of photons reaching the detector through a collimator hole or by penetrating the septa was calculated. Allowance was also made for the X-rays generated in the lead of the collimator, Finally, scatter in the crystal itself was calculated. Good agreement was found between the theoretical and experimentally measured spectra. Using gallium-67, a radiQnuclide emitting gamma-rays at several different photopeak energies, a comparison was made hetween images taken using the predicted optimal analyser window settings and ~hosejudged visually to be of highest quality. Attempts have been made to overcome this effect by channels ratio corrections, decolourisation and USe of "Cerenkov inserts". The latter were found to eliminate count rate variations due the presence of pigments and the gradual return of colour. His disadvantage is the low efficien cy~is better only for small volume inserts. This investigation was undertaken to improve the efficiency of Cerenkov ~nserts by the construction of a special vial. This is a Perpex vial (diam : 28mm, hight : ABmm~ wall thickness 2,75mm), filled with 10ml Esculin-Water solution (Ig/l) and hold in 3 externally metalized (A1) polystyrene tubes (capacity 0,5ml each, diam : 6,Smm, wall thickness 0,5mm)positioned at 6,Smm from vial axis. The radioactive solution is pipetted into these inserts. The counting efficiency is improved according to reasons : (1) the use of 3 tubes increase the surface/volume ratio compared to same total capacity (1,Sml) single tube, then reduce the self-absocpbion (2) the metalizBtian is favoutable to reflexion of light against absorption on the opaque surface (~) the Perpex vial create itself a Cerenkov spectrum (4) the Esculin convert the U.V. component of light into a visi ble one better matched to photocathode. If the percentage of counting rate, compared to that of a calourless solution without insert, is 28,2~ fnr single opaque (i,5ml) insert in standard plastic vial, its become 53,3% with metslized (1,Sml) tube, ~3,1% with Esculin so-lution~ 47,9% with 3 metalized (0,Sml) tubes in Esculin solution and 51,1% in our device. With regard to, counting the efficiency is 11 times greater and the raw counting rate/ background ratio pass from 1,15 to 8,5 for obvious human potassium measurements. Laboratoire de Biophysique, Facult6 de M~deci he, 22 rue Camille Desmoulins, 29200 BRE5T, FRANCE. QUANTITATIVE DETERMINATION OF REGIONAL EXTRAVAS-CULAR LUNG WATER BY PET: ACCURACY AND LIMITATION. G,-J. Meyer, O. Echober, and H. Hundeshagen The calculation of regional extravascular lung water from equilibrium tomographic images of the total water and blood pool requires three operational steps. 1) normalization of intravascular activities in blood pool and water volume measurements, 2) absolute calibration of the PET system, including absorption correction procedures, and 3) consideration of gradient effects in the steady state distribution of 0-15 labeled water. The errors resulting from these effects and procedures have been evaluated. Absolute intravaseular activities can not be obtained from reconstructed slices because of significant partial volume effects. However, normalization of intravascular activities in independent measurements is possible because of similar partial volume effects in corresponding slices. Absolute calibration requires blood sampling during blood pool measurement and transmission measurement for absorption correction. The gradient effect in equilibrium distribution of 0-15 labeled water ean be calculated by application of a steady state model. Since rate constant determination in compartmental modeling imposes practical problems an approach has been made to calculate the gradient effects ~rom transit times, which are easily accessible. The model can be expanded to a two compartment system which allows correction for variance of permeability and changes of the extraction fraction, thereby covering a wide range of pathological situations. It has been shown that the error on absolute rELW values as obtained by the method of con-stan~ infusion of 0-15 labeled water and single breath inhalation of C-II Carbonmonoxide is in the order of + 25%, The inter-patient variance is in the range of ~ 20%, 8~d the uncertainty in regional differences is smaller ~ 10%. In view of the clinical relevance and the difficulties in assessing regionally increased extravasular lung water, the accuracy reached so far is sufficient to answer clinical questions. Institut f~r Nuklearmedizin der Medizinischen Hoehschule Hannover. 3000 Hannover, F.E.Germany Clinical value of the alveolar epithelial pe~mea bility (ALP) in various pulmonary diseases, g_Pa lumbo*,T.TodiscoC*L.Fedeli*and P,Merante~* *Division of Nuclear Medieine.**Institute of gemeiotica Medics. University of Perugia (It. Acute and chronic damage of alveolar space (smoking habitue), of pulmonary interstitium (diffuse lung fibrosis) can produce an impairment of alveolar impermeability to aerosolized particles The purpose of this study is to verify the value of tbzs parameter (AEP) in other lung diseases such as pulmonari edema (PE).in adult cespiratory distress syndrome (AHDS), acute viral pneumonia and chronic obstructive lung disease (COLD). We chek also the degree of alveolar repair after the cessation of smoking and after a surfactsnt stimulating therapy. Method and subjects: normal non smokii~g subjects n.lOO;Smokers,n.20; COLD,n.12, V.Pneumonia,n.E; interstitial l.dis.(ILD)n.g;Pg,n.4;ARDg n.~aA.E. ~m P. was studied by the radioaeroscl method( Tc-DTPg)gxposure time,lmin.;delivered dose 15~Ci. After a continous record over the chest by comp~ terized gamma camera the clearance rates from the lungs towards the blood(Tl/2,min.and M%min) were obtained, gesults:Tl/2,min. K%,min. A 524 Perfusion-Ventilation imaging with Tc-99m NAt and Tc-99m aerosols in pulmonary embolism. L. P~yh~nen, A. Virjo, V. Turjanmaa, t. Karhum~ki and A. U~sitalo The sensitivity of the perfusion lung imaging in pulmonary embolism is high but its specificity is low. Combined perfusion/ventilation (Q/V) imaging has proved to be very sensitive and very specific, too. Lung ventilation imaging with radioactive gases is not widespread because either poor physical properties or the limited availability. The cheapest way to perform the combined Q/V imaging is to use Tc-99m labelled macroaggregates and microaerosols, In our procedure the perfusio, imaging is at first performed with reduced dose of 18 MBq Tc-MAA. After the perfusion imaging the patient inhales aerosol from a commercially available nebulizer. The air flow is 8 I/min, dose 955 MBq in 3-5 ml and the particle size less than 1.0 micron in 90%. The inhalation is continued until the count rate exceeds 2-3 times the perfusion count rate. Two point sources are used to match the perfusion and combined Q+V images exactly above each other according to a computer program. The pure ventilation images are left when the contribution of the berfusion is substracted from the combined Q+V images. We studied 35 patients suspected for pulmonary embolism. Only ii of them showed V/Q mismatch typical to pulmonary embolism. 22 patients had as a cause for perfueion defects some other reason, mostly chronic obstructive disease (COPD) (20 pts). These oatients showed typically V/Q match and they also had central aerosol deposits in larger airways. Four pa-tients showed both matching and mismatching defects and in these cases it was possible to diagnose pulmonary embolism with COPD, University Central Hospital, Dept. of Clini-cal Physiology, SF-33520 Tampere 52, Finland We reqiewed chest radiograph and perfusion lung scan in 115 patients affected by pulnDnary embolism in order to assess whether chest radiograph could assess perfusion inloai~nent as well as lung scan. Patients wee classified according to the r~diographic appearance of descending pulmonary artery: normal, enlarged,and r~arkedly enlarged with "sausage" shape. The width of the artery was also n~as%~ed . The r~ of sec~e~tal defects at perfus£on lung scan %~s used to score the degree of vascular obstruction: patients ~qith sausage shape of the artery had the most serious obstruction (10.10+2.46 unperfused lung se~s, i.e. about 56% of the total vascular bed) ; patients with r~ artery had the s~allest obstruction (4.61+-2o43, i.e. 26%); patients with ernlarged artery hut without sausage shape were intermediate between the two ~evious gro/ps (6.99~_2.45, i.e. 39%). Perfusion inlceirsent ~ras significantly differe~it (p30rlmHg). The distribution of PI in Type IV has demonstrated fairly uniform throughout the lung. 3) The distribution of VI has shown within normal in most of the patients (PCW<30mmRg). Hut in oatients with PCW over 30nunHg, the distribution of VI shows fairly uniform throughout the lung. 4) In patients with PCW over 30mmHg, VI returns to normal, but PI is not recognized the improvement of the distribution even after 6~12 months of surgical treatment. Conclusions: l) PI, VI and 9/0 are very beneficial to estimate the severity of mitral stenosis before surgical treatment. 2) It has been considered that these three indices are good markers to estimate the improvement of regional pulmonary perfusion and ventilation along with the improvement of hemodynamic data after surgical treatment. The purpose of the study was to compare the results obtained with two different regional lung perfusion analysis systems. 62 consecutive patients were studied. At first a perfusion study was made with I mot of Xe-135 using Kefut RI 1200 device and immediately thereafter with 4 mOt of Te-99m MAA using gammacamera. Perfusion studies with Xe-133 were made with Kefut BI 12OO regional lung function analyze~ in which there are 16 detectors arranged in four pairs on both anterior and posterior sides of the patient adjustable according to lung height. In the equipment an automatic data collection and analysis is performed by a minicomputer. In this study percentual distribution of blood flow in the 16 lung areas was calculated. In the Tc-99m MAA perfusion studies a large field of view gammacamera with a minicomputer was used. Both anterior and posterior projections were imaged, Corresponding 16 lung areas as in the Xe-133 study were selected with ROIprogramme and %he peroentual distribution of lung perfusion was calculated. Paired Sudent's t-test was used in the statistical analysis. Although the distribution of lung perfusion was rather similar with both methods, some small but significant differences were found in the right lowest and cardiac areas, which can be interpreted by the differences in the techniques and also in the energies of Xe-133 and Tc-99m. We conclude that both methods yield reliable information about regional lung perfusion but the use of Kefut BI 1200 lung function analyzer is much easier than the computerized gammacamera method. PXij~t-B~me Central Hospital SF-15850 Lahti, Finland VOLUME WEIGHTED DISTRIBUTION OF XE-133 WASHOUT CONSTANTS -AN IMPROVED METHOD FOR MEASURING REGIONAL LUNG FUNCTION S. Hy6dynmaa and ~. L~nsimies With the use of gamma cameras and computers in dynamic lung function studies pixel-by-pixel calculations of Xe-133 washout half times have been performed. In this work we calculated the volume weighted distributlon of the washout constants to improve the analysis. Xe-133 (200 MBq) was administered intravenously and two minutes of rebreathing were allowed for equilibration of the gas with regional volume. The washout phase was ~ollected to a Gamma-]] computer as 3 s frames for 3.2 min (64x64 matrix). The washout time constants were calculated from the ratio of initial volume and 30 s washout images. The distribution of the washout constants was generated from the washout constant image so that each picture element contributed to the distribution by the~s2ght determined by the volume image. The method was tested with six vol~mteers. The average ef the mean washout constant of the distribution was 0.045 ± 0.004 s (±SD), which corresponds to a mean half time of 15.3 s. We conclude that the analysis offers an improved method for examining the regional lung ventilation giving the perfusion, lung volume, washout constant image and distribution. The volume weighted distribution of the washout constants also allows the estimation of the volume affected with decreased ventilation through area determination from the distribution. Factor analysis of dynamic structures (FADS) allows to extract the few main components in a set of dynamic data. It associates an activity time curve (factor) with the spatial distribution of the corresponding events (factorial image). We applied FADS to scintigraphic studies of lung ventilation using Kr-glm in 5 normal subjects and 2 patients (COPD and lung cancer). Looking for 3 components, we studied the influence of both lateral decubitus (LD) with respect to dorsal decuhitus (DD) on these components. If the dynamic curve representing each factor received only few variations in normals, their corresponding image was altered. The ist factor associated with a strong ventilation located at both bases in normals in DD posture, almost disappeared in the non-dependent base while the dependent base was reinforced. To a lesser extent, the same type of asymmetry occurred in the 2nd ventilation factor, showing the entire intrathoracic region. The 3rd factor, showing the delivery of the tracer bolus in the large airways and in the lungs, was Rot significantly modified by posture. For patients in DD, the Is% factor involves the whole lungs, as well as the bases. In LD, the asymmetry between the dependent and non-dependent lung is considerably decreased with respect to normals, indicating a decrease of the proportion of ventilation in the dependent lung. The 2nd factor does not show significant redistribution of ventilation in one case and a phase shift of the ventilation between DD and LD in the other study. Interpretation of third factor changes remains difficult since a better understanding of patient data implies the need for a 4th factor. Thus, FADS appears to be a promising tool for the physiological interpretation of the distribution of ventilation, particularly to explain the effect of posture changes. Recent studies have demonstrated that 99mTc-Glucoheptonate (Tc-GN) accumulates in primary lung cancer. This study was undertaken to compare the diagnostic usefulness of Te-GH and Gallium-67 (Ga 67) thoracic scintigraphies in detecting hilar and mediastinal spread of lung carcinoma. We prospectively studied 36 consecutive patients with newly diagnosed lung cancer. The primary neoplasms were visible on chest radiographs and were histologically proven (22 squamous-cell, 9 adenocarcinoma, 4 large-cell and 1 small-cell carcinoma). Within a one week period, all patients were evaluated sequentially with Te-GH followed by Ga-67 scan, mediastinoscopy,and, if indicated, thoracotomy. Anterior, posterior and if necessary, oblique thoracic scans were performed using a large-field-of-view camera 6-9 hours after i.v. injection of 25 mCi of Tc-GH. Immediately after the Tc-GE scan, patients received 6-9 mCi of Ga-67 and images were obtained 48-72 hours later. All primary lung tumors were detected by Ga-67 scans while 32 tumors (89%) accumulated Tc-GH. Using an intensity grading system for tumor uptake of both ragiotracers, Ga-67 showed a better accumulation and higher tumor-to-background ratio in 47% of cases. Fifteen patients had a positive mediastinoscopy: mediastinal spread was detected by Tc-GN in 9 patients (60%) and by Ga-67 in 13 patients (87%). Of the 5 patients having hilar involvement confirmed at thoraeotomy, 4 were visualized by Tc-GH and all 5 were diagnosed by Ga-67. Although the number of cases is limited, these results suggest that Ga-67 is more accurate than Tc-GH for the detection of intrathoracic metastatic spread of primary lung carcinoma. Because of its low sensitivity (60%) Tc-GH cannot he recommended for the clinical staging of primary lung cancer. Previous reports on the role of multiorgan scan -liver scan (LS), tone scan (US), and brain scan-for the detection of lung cancer meta L tases have sh~n no agreement on its value. A retrospective study of lag patients with proved lun~ cancer has been carried out. According to hystology they were classified as: 29 adenocarcinema, 47 squamous, 43 small cell, and 3 large cell. Each patient had the three scans done with a I,FOV camera and the results were compared with the clinical and biochemical data for each organ. The rates of metastases detected were: 11% (13/122) for liver, 13% (16/122) for brain, and 19% (13/122) for bone. Occult metastases were detected in 3,5% (3/86) for LE, 5,6% (6/107) for brain scan, and 9,5% (8/84) for BE. In 31% (38/122) of patients at least one scan was pos! tire, 13.6% being occult metastases. Liver funs tion tests (LFT) and alkaline phosphatase had a high non specificity: 72% (26/36) cf cases with abnormal LFT had normal LS, and 60% (22/38) of cases with elevated alkaline phosphatase had normal BE. According to bye%elegy the detection rate was: 35% (iO BE, 8 LS, 5 brain scans) for small cell, 34% (7 Rg, g L2, S brain scans) for adeno carcinoma, end g5% (5 BE, 2 LS, 6 brain scans) for squamous. These results surest that multiorgan scan is of value, both detecting occult metastases and showing the non-specificity of LFT and alkaline phosphatase. Servieio de Medieina Nuclear. Hospital National "Valdecilla". Santander. Spain. EVALUATION OF PHASE AND AMPLITUDE IMAGES FROM FIRST PASS CARDIAC STUDIES. P.Bourgeois 1 F.Erbsmann and J.Fruhling. Phase and amplitude images analysis are systematically performed in the famework of the semiautomatic cardiac first pass studies treatment program which has been developped in our department. In order to establish tbeir~value, 67 series of such images obtained from first-pass (FP) studies alone ( 33 ) or combined FP-Multigated (MUGA) studies ( 34 ) have been compared to the corresponding images obtained from classical MUGA studies performed in the same incidence the same day in 34 and later in II cases. All patients underwent also electrocardiographic, echographic and scintigraphic ( 2OITL or 99mTc PP ) investigations as well. Analyzable amplitude images could not be obtained in one case at right and in two at left but with regard to phase images, in 4 at right and in 23 at left. In all cases but four ( 2aneurysms and 2 akdnesias ) out of 45, phase and amplitude images obtained from FP and MUGA studies performed successively were superposable and gave the s~me informations. In the 22 cases of FP alone, phase and amplitude a~nc~n~alities correlated well with other data. Tn two cases, multigated sudies were not contributive owing to arrhytmia but first pass well. Comparison between images obtained at the time of Pyrophosphate scan FP and images from the combined FP-MUGA performed in the same patients (~I) one to two weeks later showed the technique to be reproducible. It is concluded that valuable amplitude and, -at the present stage of the program -to a less extent, phase images can be obtained from first pass cardiac studies. Aneurysms however donot seem to be clearly diagnosed, but well hypokinehic and akinetic segments. Departement autonome des Radioisotopes, Centre Hospitalier J.Bracops, 79, rue Dr Hoot, ~O70, Bruxelles, Belgique. The use of phase images in the analysis of gated cardiac studies is now well established. Of the various methods available for obtaining phase and related images, four were chosen for intercomparison. These were: (i) conventional single-Harmonic Fourier phase imaging. (ii) time-to-minimum functional imaging following multi-harmonic Fourier curve-fitting. (iii) Factor imaging following polar transformation (factorial phase imaging). (iv) Factor imaging following oblique transformation (physiological factor imaging). These methods were compared for 100 patients using a perception experiment I in which observers were asked to rate the degree of abnormality in each image. The results were then analysed using receiver operating characteristic curves. Statistical parameters measuring mean~ variance i and co-variance of phase over the left ventricle were calculated and compared for each method. An interpretation of these parameters is included. Factorial methods were shown to he extremely useful but required greater operator training and longer computer times. Hospital t gaslar~ Gosport, Hampshire PO12 2AA, England. CORRELATION OF PHASE AND AMPLITUDE IMAGES WITH MODERATE AND SEVERS CORONARY ARTERY STENOSIS. D. Kyriaki-Manolaraki, S. Rokas, D. lWaintas, C. Zerva, P. Kostamis, S. Moulopoulos and C. Zonstantinidis. It is possible for normal wall motion to Occur in the presence of significant coronary artery stenosis. The abi]ity of phase and amplitude parametric images to detect wall motion abnormallties in moderate (60-80%) and severe (81-]00%) coronary artery stenosis revealed by coronary angiography (CA) was estimated for patients with ischaemic heart disease. From a total of I00 patients who underwent radionuclide ventriculography (RV) and CA, the results from 33 patients are presented. The RY was performed at rest in the LA0 40 ° projection and the average time between the RVand CA was 7.5 days. The phase and amplitude images were graded as normal, and mild, moderate and severe abnormalities. The areas of the left ventricle studied were: The anterior septum, the anterior, the lateral~ the posterior and the inferior wall. The max sensitivity for the phase image was 77.8% for severe angiographie abnormalities of the anterior wall and the rain was 20.0% for abnormalities in the lateral wall. For amplitude the max was 71.~% for moderate abnormalities in the ant. septum and the min was 0.0% in the inferior wall. For phase and/or amplitude the max was 81.2% in the anterior and the min was 33-3% in the lateral wall_ The specificity ranged from 100% in the lateral wall to 72.2~ in the posterior wall. The Overall sensitivity was 64.3% and the overall specificity 83.6%. It can be concluded that phase and amplitude images derived from RV have a high specificity but only a moderate sensitivity for detecting moderate and severe degrees of coronary stenosis in pts. with ischaemic heart disease. Div. of ihclear Medicine. Dept. of Clinical Therapeutics, Athens University, "Alexandra, Hospital, 80, Vas. Sophias Ave., GR-115 28, GREECE. IMPROVING METHODS FOR TH~ LOCALISATION OF PARATHYROID LESIONS. M.L. Wastie, F.D. Smith, A.C. Perkins and J.G. H~rdy. Ten patients ~_th biochemically proven primary hyperparathyroidism were imaged using TI-201 with Tc-99m subtraction. Each patient was imaged 5 minutes after am intravenous injection of 70 MBq Tl-SO1-thallous chloride followed by administration of 70 MBq Tc-99m-sodium pertechnetate through the same canula. After allowing 10 minutes for pertechnetate localisation a Tc-99m image of the thyroid was recorded. To minimise movement artefacts the patient gs head~ neck and shoulders were supported in a vacuum immobiliser. Subtraction of the thyroid image from the thallium image resulted in clear visualisation of the abnormal parathyroid glands in nine patients, These findings were confirmed at surgery. Images of one patient showed abnormal uptake throughout the left lobe of the thyroid which was found to be a psmathyroid carcinoma. Follow-up imaging one month following surgery showed no pathological uptake. Thallium uptake was particularly helpful in locallsing an adenoma in the mediastinum whfch was well demonstrated without the need for background subtraction. T1-201 was administered during surgery and a small sterile radiation probe was used to aid the excision. Hg-K--X-rays (66-84KeV), TI-201 emits gamma rays at 136KeV (2%) and 167KeV (8~). We proved that the influence of these sparse TI-201 gamma rays on a TcO 4 thyroid image was negligible. Hence we propose an alternative procedure based on an inversion of the TeO4/T1-201 injections (T1-201 before Tc04). As opposed to the original method, this allows a simplified data processing procedure without deteriorating the accuracy. After injection of ImCi TI-201, the patient is positioned under a gamma camera. A 300kcts image is acquired. Without moving the patient, ImCi TcO is injected and 10 minutes later a 300{cts TcO 4 thyroid image is taken. Both images are background-subtracted and normalised. After subtraction of the Tc04 image from the TI-201 image, hot areas were considered parathyroid tumors. Scans in 5 patients showed a total of 8 residual hot areas. Four of these were parathyroid adenomas, two were hypertrophied parathyroid glands, one was a thyroid adenoma and one was an artefact. One hypertrophied gland was not seen. Beside parathyroid tumors certain other lesions may be visualised: thyroid nodules, active lymphe nodes and veins. The modification of the data acquisition protocol will not influence this lack of specificity of TI-201. Both lllln-labelled platelets and 99mTclabelled fibrinogen have been proposed for detecting deep vein thrombosis -D~Ff-in the calf, thigh and pelvis. We have compared the two methods in a group of 50 patients to date with either clinically suspected DVT (38 patients) or at risk of DVT following fractured neck of femur (12 patient~ . All patients were scanned 24 hours after injection of autologous lllIn-labelled platelets, then underwent bilateral ascending venography and thereafter 99mTc-fibrinogen scanning. Twenty-five patients were receiving anticoagulants (21 heparin and 4 warfarin) at the time of study, Thrombosis was recorded as being detected in calf, thigh, or pelvis by each method. Venography detected thrombosis in 44 sites in 95 limbs studied, lllIn-platelet scanning detected thromhosis with a sensitivity of 48%, specificity of 97%, positive predictive value -PPV -of 75% and ~egative predictive value NPVof 91%. 9 mTc_fihrinogen scanning gave results of sensitivity 39%, specificity 93%, PPV 52%, and NPV 89%, Anticoagulation did not significantly influence the results. It is concluded that radionuelide imaging with lllln-laballed platelets is a useful technique in the detection of DVT and superior to imaging with 99mTe-fibrinogen. University of Aberdeen, Department of Bio-Medical Physics and Bio-Engineering, Foresterhill, Aberdeen AB9 2ZD, Scotland. The current methods of thrombus imaging are less than ideal and essentially limited to the extremities. We have investigated the possibility of imaging thrombi located in the trunk by using an antiplatelet monoclonal (7E3) antibody labeled with 1-123 (chloramine-T method) or In-Ill (antibody -DTPA conjugate). The specific activity of the 1-123 and In-lll preparations was 20-300 pCi/pg and 10-30 ~Ci/Bg, respectively. The antibody is an Egg i that binds to the glycoprotein 2B-3A complex on human platelets and blocks ADP-indueed aggregation of both human and dog platelets by inhibiting the binding of fibrinogen to the platelet surface. When radiolabeled 7E3 antibody was incubated with whole blood (0.13 pg/ml) and the mixture then clotted with thromhin (I U/ml) 68% of the radioactivity remained with the clot despite repeated washing. Initially, uptake was high in the dog liver with subsequent accumulation in the spleen. Blood activity persisted for up to 24 hr. Venous or arterial injury sites were consistently localized but intravenously formed thromhi (isolated vein segment injected with thrombln and formed clot released) was not always reproducible probably due to their low platelet content. However, arterial thrombi produced by placement of a copper wire into s lobar pulmonary artery were easily detected whe~ platelets were labeled exvdvo by incubation of whole blood with radiolabeled antibody (without washing) before relnjecting. No blood pool subtraction was necessary for this procedure. We conclude that radiolabeled antiplateiet monoclonal antibodies should be investigated in humans for iocallzlng arterial thromhl in the pulmonary and coronary elrnulation, intra-cardiac thrombi and sites of suspected vascular damage with clot formation. Medical Dept., grookhaven National Laboratory, Upton, New York, USA. Work performed under contract DE-AC02-76CHOOHI6 with the U.8. Dept. of Energy. Tc99m PLASMIN TEST USING PROBE AND GAg~ CA~AKA FOR DETECTION OF D~P VEIN THROMBOSIS. R.A.Vald6s Olelos and H.J. Serdijn. Tc99m plasm//~ test, a rapid and sensitive test in the diagnosis of deep vein thrombosis (DVT) , is usually performed with a NaI probe system (Lysotec) 10-30 minutes after /_njection of 17.5 of Tc99m plasm/J] (Lysofibrin) . Counts are made at 10-15 points on the legs with the lower extremities elevated 45 degrees. An increase in radioactivity is considered to be suggestive of DVr and is expressed in Q units. Criterion of a positive test is at least three points adjacent on the suspected leg with an increase in uptake (>13 or .<-3) , or one poinh with more than 13 or less than -13. We use the probe method as an initial screeningtest for DVT in otrc hospital. In 25 patients with clinical suspected DVT and with a positive probe test we performed consecutively a test using a garsna car~era (LVOF~ siemens). 300-400 k-counts views of ankles, cal yes, ~neeregions (posterior) and thighs/pelvis (~/]terior) were made with the legs elevated between 10 and 30 min. after a second injection of 370 MBq Tc99m plasmin. Dynamical data obtained with a Ganlna 11 system were processed and the Q-expressions were calculated from I 0-15 symmetrical ROI's delineated on the deep vessels of the legs. Gaalr~ camera test was positive in 24 of 25 patients. Most frawes showed hot spot with or without veinocclusion and were interpreted as ccapatible with DVT. Some studies with c~ly diffuse uptake were considered as low probable U~T. Specificity and sensitivity of this sciztigraphical imaging interpretation using X-ray phlebography as a reference method has yet to be determined. Here we have a prospective study in progress. We conclude that Tc99m plasmin test with garm~ camera and computer processing is a easy,rapid and sensitive test for D~T probable due, among other factors, to a real thrombous uptake of plasmin. Scintigraphical imaging promises a high specificity in the diagnosis. Regions of interest were selected over cranial and caudal right lobe, over the left lobe and over the entire left ventricular myocardium (H). The sum over the liver lobes gave total liver (L), Data were corrected for labelled free iodide. Mean count ratios per image element H/L were < 1,25 in controls; a mean H/L of 1.5 indicated moderately reduced U with various degrees of inhomogeneity (group I) while a mean H/L of 5.2 represented extremely reduced U and inhomogeneity in liver scans with HA (group II), -In some P of group I Tc-g9m-sulfur colloid scan was nearly normal. It was always abnormal in group 11. The mean ET in controls was 21 + 5 min., in group I it was 25 min. and in group II it was for the total liver 120 min,, but 50 min. for left lobe and 213 min. for right lobe (range 44 to 881 min.). -An elevated serum cholesterol and triglycerides was corrected with a prolonged ET in group I. Kinetics of HA (U and ET) permits the distinction between alcoholic fatty liver and alcoholic cirrhosis. There are different HA kinetics in cirrhosis for right and left liver lobes. Metabolic alterations concommittant with hyperlipemia are also recognized. In this study we evaluated to which extend global disturbances in 123-I-heptadecanoic acid (IHA) kinetics reflect alterations in hepatic fatty acid metabolism as they occur in cirrhosis or diabetes. The study included 5 normal subjects, 17 patients with liver cirrhosis (12 alcoholic, 5 postnecrotic) and 12 diabetic patients. After injection of I mCi carrier-free IHA, dissolved in 6% human serum albumin, serial images with a frame rate of I/min. were recorded in anterior position. The relative hepatic IHA uptake between 5-20 min after injection was measured as the ratio of the mean count rate per pixel in a hepatic ROI to the mean count rate per pixel in a myocardial ROI. IHA elimination rate in liver and myocardium was measured as the disappearance constant of a mono exponential curve fitted through the descending part of time activity curves calculated on the original data in both ROI. The most striking alterations in hepatic IHA kinetics were observed in alcoholic liver cirrhosis: a decreased uptake and elimination rate in the liver, whereas myocardial elimination was not significantly different from the control group. In contrast, postnecrotic liver cirrhosis only caused a less importantly delayed hepatic elimination of IHA. Diabetes was characterised by alterations in hepatic as well as in myocardial IHA kinetics. These changes in IHA kinetics, even without correction for free iodine, clearly reflect the effect of alcohol on liver metabolism and the effect of an increased pool of unesterified fatty acids in diabetic patients. This information is not directly available by conventional diagnostic modalities. AZ-VUB,Laarbeeklaan I01,B-I090 Brussels. A 567 DIAGNOSIS OF ACUTE CHOLECYSTITIS BY TC-99m -IDA CHOLESCINTISRAPHY. L. Lanzberg, S. Lanzberg, M. R. Quastel and G. ~%odadadi. The rapid and accurate diagnosis of acute cholecystitis is extremely important and sometimes presents a difficult clinical problem. For many years, radiographic evaluation of suspected cholecystitis has depended on the use of iodinated contrast material. More recently, ultrasonography has proven to be of much value for the assessment of cholelithiasi~% An alternative method for the investigation of the flow of bile in the biliar I tree in patie/uts with a clinical picture of suspected acute cholecystitis is the use of the Technetium-99m-IDA scan. This examination offers excellent visualization of the biliary system and supplies functional information as to the patency of the cystic duct. We have studied 116 consecutive patients with abdominal complaints suggestive of acute cholecystitis. Scintigraphic examinations were performed for: 2~ hours following the intravenous administration of 4-5 mci of the agent (HIDA or DIPA). Our results showed that in 46 of these patients, the gall bladder was not visualized by scintigraphy. Of this group of patients, 41 were found to have acute cholecystitis at the time of surgery. Normal IDA scans were observed in the remaining 70 patients, none of whom were subsequently judged to have had acute cholecystitis. According to our results, comparing the scanning results with operative diagnoses, the sensitivity of the IDA scan was near 100%, in that no proven case of acute cholecystitis had visualization of the gall bladder. The specificity was found to be about 90%. In the remaining cases of 5 false-positve IDA scans, 4 patients had chronic cholecystitis, and one pancreatitis. Thus, visualization of the gall bladder by IDA scanning virtually rules out the possibility of acute cholecystitis. We evaluated the diagnostic impact of TC-99m abdominal blood pool scintigraphy (ABPS) in the assessnent of gastrointestinal (GI) bleeding whose cause could not be found by upper GI endoscopy and siQ~s~idoscopy. In the four year period prior to availability of ABPS, 26 patients with acute or intermittent GI bleeding underwent GI contrast angiography; it demonstrated an abnormality in 12 cases (most cca~only angi(~dysplasia), but in only 4 cases (l.0/year) was active bleeding seen. In the first 18 months after the availability of ABPS, 71 scans were ~>~r formed on 43 patients. The ABPS demonstrated active bleeding on >I occasion in 14 patients (33%) (9.3 per year); the site was jejunum in 3, ilet~n in 3, ileocolic in 2, right half of large bowel in 4, and surgical wound site in 2. ABPS localisation was confirmed (within 5-10 c~,s) at subsequent surgery or angiography in all but 1 patient, in %~icm surgery or angingraphy was contra-indicated. Evidence of interval bleeding bet~en delayed images (separated by several hours) was seen in 9/43 patients (21%); in all of these ABPS showed static colonic activity; 1 had carcincrna of the caecum, 3 were found to be bleeding from the upper GI tract, and in 5 no cause could be established. There was no ABPS evidence of any bleeding in 20/43 patients (47%). Eleven patients bad both ABPS and Gl angiography. Is all 5 patients in whom GI angiography showed evidence of active bleeding, ABPS also did. In 2/5 patients without ABPS evidence of active bleeding, GI angiography demonstrated oesophageal varices which may have caused bleeding. conclude that introduction of ABPS markedly increases detection of active GI bleeding in both the ~all and large bowel. It may also increase the yield frc~ GI angiography. ) , though the SCWF~I is only a special case of stochastic approach. The stochastic approach reduces to a ~CWM/~ in the case of constant infusion with negligible decay, and only in such situation is the approximatlon of good mixing really valid. This approximation cannot be extended to wash-out and short-lived isotopes studies in general because in such situations the definition of volume of distribution and/or partition coefficient are not strictly appropriate, Assumption of good mixing is equivalent to the assumption that the impulse response function of the considered system is monoexponential (as in Kety-Schmit equation). That cannot be generally true since shape of impulse response function is dictated by the expectation of the existence of a minimum tmin, a most probable t D and maximum transit time. Hence, the ~onoexponential behaviour of impulse response function should be seen as an approximation, albeit a good one when tmi n ~tD~--O. Under the circumstances which a~e defined by the physiological properties of the system, it may be expected that SOWMM is a good approximation and that constant volume of dist= ribution of tracer may indeed be defined. The question of whether, in a particular application, an isotope may be regarded as "long-" or "short-lived" depends not only on its life-time, but also on transfer properties of the considered system. The stochastic approach takes into account the transfer properties of the considered system and the distribution of tracer in the system not requiring a hypothesis of good mixing and providing a possibility of evaluating corrections for decay. Klinicka Rolnisa,Zagreb,Yugoslavia NEW POSSIBILITIES FOR QUANTTTATIVE MEA-SUREMENTS OF REGIONAL CEREBRAL BLOOD FLOW BY THE USE 0F 195m AURUM. P.Linder and O.Niokel The new isotope 195m gold allows quantitative rCBF measurements, following a previously published theory by Linder. The energy-spectrum of the generator eluate shows two strong photon peaks, one at 68 keV, the second at 262 keV. Both energy levels have a half life of 30.5 sac. This enables dynamic brain perfusion studies not only in dorsal projection (262 keV) but also in both lateral projections (68 keY) within some min without the need of a background correction and without significant "look through" effect. It is also possible to generate functional images which show the speed of inflow, the persisting time distribution pattern and a quantitative mapping of cerebral blood flow. The local resolution is about 1-2 om. The accuracy of the method is better than 5 %. Normal CBF values for adults are 44°5 ml/min/lO0 g Z 5 %.The method was tested in 40 patients with angiographioally proven carotid stenosis before and after vascular surgery. The results prove that the intracerebral haemodynamic relevance of carotid stenosis can be quantified. Dynamic perfusion studies and the computed trend pictures of lateral views of the patients after stroke shows the area of occluded vessel and its decreased regional CBF. 8 volunteers have been investigated in left lateral projection twice within 5 min: the first study was performed with closed eyesat rest, the second study with open eyes fixing a moving subject. The results: the local changes in the visual cortex has been up to 30 %, mean hemispheric changes up to 8-10 %. The area of the visual eortex and a weaker increase in the stimulated movememt centers can be clearly deteotedo-Municipsl Hospital, Dpt of Radiology, D-8390 Passau,W-Germany Special parameters: TT4, TT3, rT3, TUG, TT4/TBG and TT3/TBG ratio, TSN receptor AB (TRAM) Indications: I. euthyroidism(confirmation): FT4, FT3; 2.hyperthyroidism: FT3* (+ TRH-test TRM-test in borderline cases); differentiation by TRH-test TRH-test); b) hyperthyroidism: FT3, FT4 (+ ABS, especially TP~AB, in Graves' Disease); c) hypothyroidism: FT4, basal TSH (TRH-test); d) differentiated thyroid carcinoma: hTg, hTg AB, TRNtest during TSH suppression. The new TSE IRMA may render some of the TRN-tests unnecessary in 2 Changes in liver metabolism following chronic alcoholic consumption were studied by dynamic scintigraphy (DS) after i.v. injection of 3 mCi HA. Degree of uptake (U) and elimination halftimes (ET) were determined in anterior view for 40 minutes, in 10 patients (P) with fatty liver (group I) P without liver disease were controls. Diagnosis was based on liver biopsy In all patients with RV preexcitation, the earliest contraction, area appeared in the RV, while the mean RV phase proceeded the mean LV phase.Patients with left-sided preexcitation had precontraction in the LV, and the advance of mean LV phase. Patients with septal preexcitation had normal or nearly normal ventricular activation patterns and no significant differences between RV and LV mean phase angles.The procesure seems to be an accurate noninvasive method of assessing abnormal sites of initial ventricular acti- 12 patients with WPW and 12 with LGL syndrome were investigated by ECG-gated blood pool ventriculography at two different points of time. The data acquisition was carried out from 3 different directions /LA0-15, LA0-30, IA0-45/ by a Hungarian computer system in each investigation. The secuence of contraction of the ventricle walls was analysed by the help of the phase display method by two undepending observers. The ventricular preexcitation could be identified unambigu/ously in ll cases of 12 patients with WPW syndrome on the basis of the ventricle, corresponding to the 12 lead ECG findings. In one case the accessory pathway near the septum could not be identified /sensitivity: 92 %/ An early ventriculary contraction was diagnosticated falsely in 3 of the 12 patients with LGL syndrome on the basis of phase display method /specificity: 75 9~/. The reproducibility of the used method was verified by repeated investigations. The use of several directions of data acquisition proved to be usefull especially in cases of accessory pathways near to the septum or on the posterior part of the basis of the left ventricle. The authors in order to prove their preliminary results used the body surface mapping method which according to literary data is also suitable to localise preexcitation in non invasive way. They draw in their report their conclusions on the basis of experience received from an essentially increased case-number. LV function during exercise has been evaluated in 2 patients with LBBB and 6 patients with programmable RDF (RDP 2, alpha, ESln, FRG) implanted for complete AV block, bradyarrhythmia or sick sinus syndrome. Equilibrium RNVG was carried out at rest as well as during exercise (multistage, graded tread mill ECG test) and global (GEF) and sectorial ejection fraction (SEF) were measured. Regional asynchronia was quantified by Fourier's analysis and determination of sectorial phase shift. With increasing heart rate (~) during exercise, %he LBBB patients presented increasing 8PH and decreasing SEF in the posterolateral (PL) region of the LV wall. This prevented an increase in GEF in I patient and even caused a gradual decrease in GEF in the other patient. Maximum cardiac output (CO) occurred with sub-maximum HR of 115 %o 150 bpm. HR dependant increase of SPH and decrease of the PL wall was also found in 6 patients with RDP. In ejection fraction. The present paper reports the {esults of first pass-RNV in 24 patients with LBBB and compares the regional wall motion analysis with the findings of 2D-echocardiography. The radionuclide ventriculograms were obtained using a multicrystal gamma camera with high count rate capability (Baird Atomic System 77). 99m-Tc-pertechnetate or -more recently -195m-Au was used for bolus injection. 10 patients had a supine rest study only, in 14 an additional exercise investigation was performed. The use of phase analysis,amplitud image,eje~ tion wave and phase histogram obtained by Fourier analysis have allowed to get physiological information concerning to the sequence of ventricular emptied and its modifications due to disturbances of electrical conduction.Material & Method: It has been studied 35 patients,7 with RBBB and 28 with LBBB. 8 normal subjects were used as control group. At a first step The F.analysis was appliedon the total image,beeing the phase histogram very often not demonstrative of the differences between LV & RV emptying. By this reasons a second step was carried out,in which F.analysis was obtained from ROI in each ventricle,showing an indepen~ dent phase histogram. Overlapping both of them was easier to figure out the differences between both ventricular emptying.Results: In the control group the phase histogram showed a difference of less tha 5 ° in 6 cases. In the two remaining ones the differences obtained were 8 ° & 10 ° respectively. In 4 normal subjects the nadir was in the same frame in 3 was delayed one frame in LV and in one was ~alayed one frame in RV.LBBB: from 28 patients studied,18 (64%) showed differences > 20°;S were in the range 15°-20 ° and 2 in the range 10-15 °.RBBB: The differences betweeh both apex histograms (LV&RV) were less significatives. In 5 cases the range was 15°-20 ° and in 2 was I0°-15 ° . ( In all these patients the ventricular activation was delayed in RV ).Conclusions: The ejection wave and phase ima ge obtained by F.analysis from total image ares less demonstrative than those obtained separately from each ventricle mainly if we use ~2 frames instead of 16. Previous investigations have shown that age 250 yrs., thyroid weight >50 g, thyroid nodules and a non-homogeneous thyroid scan are simple but not specific indicators of autonomy in pts. with euthyroid iodine-deficient goitre, who show a subnormal TRH test. Together with the existence of endocrine ophthalmopathy and increased titers of microsomal antibodies these symptoms were used in a cumulative way for a trial to separate 326 hyperthyroid pts. without autonomous adenoma into those possibly having non-immunogenic (NIM-HY) and into those possibly having immunogenic (IM-HY) hyperthyroidism.In order to prove that this way of separation has a sufficient probability of beeing correct Thyrotrophin displacing activity (TDA) was determined in 120 hyperthyroid pts. separated independently by the symptoms mentioned above. The incidence of TDA in 57 pts. classified as possibly having IM-HY was 79 % and in 63 pts. classified as possibly having NIM-HY was 3 %. The low incidence of TDA in NIM-HY was in the same range as in 237 pts. with euthyroid goitre and euthyroid or hyperthyroid autonomous adenoma. It is now well ack~itted that TSI are involved in the pathogenesis of Graves'disease. The aim of this work was to establish an assay of TSI helpful in the clinical diagnosis and follow-up of hyperthyroid patients. The method was developed starting frc~a the method described by Kleinman et al. (J.Lab.Clin.Med., 1980, 95:581) using h~nan thyroid m6s~ranes.Thyroid adenylate cyclase-stimulating activity was detelqnined by the generation of cyclic (32p) AMP after incubation of thyroid m~mbranes, immunoglobulins (IG) and (32p)ATP. IG were purified by ammonil~n sulfate precipitation followed by desalting by chrc~atography on Sephsdex G-50 gel. The results were expressed as percent of basal activity (100%). In 26 assays using 4 different ma~branes preparations, the average basal activity (BA) was 183 pmoles cAMP/rag prot. generated in 15 sin (CV 8.8%). The response to NaF (20 raM) stimulation averaged 743% of the BA (CV 9%). The validity of the test was further ascertained by testing TSI positive IG which yielded a response of 175% (CV 7.6%) versus ~ormal IG (105%, CV 6.7%). Clinical evaluation was perfoxed in 92 patients referred to the thyroid clinic : 32 patients were found to be negative, 60 positive. All 32 TSI (-) patients did not present any symptc~ of hyperthyroidism. Among the 60 TSI (+) patients, 28 were clinically euthyroid and 32 hyperthyroid. The followup of the euthyroid TSI(+) patients revealed a relapse in 3 cases. The clinical interest of this assay was confixraed by the finding that 12 out of 13 newly diagnosed Graves patients were TSI(+) . In addition, in 23 patients presenting with ophtalroopathy, 19 (83%) were TSI (+) : 12 of these patients were euthyroid and 7 hyperthyroid. These results are in agreesent with recently published data. In conclusion, the proposed method is adequate for evaluation management of patients with Graves' disease and as such useful for routine analysis. Depart6~ent of Nuclear Medicine,University of Louvain Medical School, Brussels, Belgium. Thyroid routine in vitro diagnostic procedures are developing continuously in direction of higher diagnostic sensitivity/specificity and also simplicity. The latest developments are: FT4, FT3, hTg antibodies (AM), TSM receptor AB and sensitive one-day TSH by radioligand assay (RLA) as well as by enzymeligand assay (ELA). During the past fou~years we presented a series of data especially underscoring the very high laboratory performance and high clinical value of FT4 and FT3 and the very high clinical value of hTg. Up to recently FT4 and FT3 were offered alternatively to the T4/TBG and T3/TBG ratio. hTg by RIA has already substituted 2 -3 years ago for the routine whole-body scan with 1-13i in otherwise complete follow-up of differentiated thyroid carcinoma. Furthermore, recent evaluation of two new sensitive one-day TEE LA (IRMA and ELISA) on monoclonal antibody basis revealed an especially high laboratory and clinical performance of the IRMA with good separation of eu-from hyperthyroidism by basal TEE. Based upon our experience as well as upon the literature we recently changed our routine diagnostic program as offered to the in-and outpatient clinics of our ~iversity accordingly as presented below: Recently, there have been promising reports on the value of T1-2O~ scintigraphy for the evaluation of benign and/or malignant thyroid nodules (R. 0CHI, etal., C~TCER 50:236-240, 1982) showing a 95% sensitivity and a 90% specifity. It was the purpose of this prospective study to test the usefulness of T1-201 thyroid scanning for decision making in patients presenting with cold nodules. 26 consecutive patients with scintigraphically cold nodules underwent quantitative thyroid scanning immediately after i.v. injection of 2.0 mCi TI-201 8nd 3-4 hrs later. ~\l patients subsequently underwent surgery for extirpation of the nodule or thyroidectomy, respectively, so that in all cases the final diagnosis was proven histologically. According to the score given by 0CHI increased uptake in the cold nodules relative to normal thyroid tissue on both the early and the delayed scan was considered malignant (positive), whereas similar or decreased uptake was interpreted as benign (negative). Five of the 26 patients had malignant nodules. However, only 3 of these revealed positive scans (60%), whereas 2 were false negative. Out of the 21 patients with benign nodules 17 had a true negative scan, while h demonstrated a malignant pattern (false positive). In conclusion, the results of this prospective study do not confirm the previous optimistic reports on the usefulness of thyroid T1-201 scintignaphy for the diagnostic evaluation of cold nodules, ~;hieh is in our experience only of limited diagnostic value, with a sensitivity of 60% and a specificity of 80%. Following injections of 99mTc Rhenium Sulphur Colloid into the second interdigital space of 55 limbs, images of the ilio-lnguinal lymph nodes were obtained at 38 mins., I, 2 and 3 hours using a gamma camera. 34 limbs (26 patients) had the clinical and radiological features of primary lympheedema, 10 limbs (8 patients) had venous oedema, and 12 limbs (6 volunteers) were normal.The ilio-inguinal lymph nodes were visuallsed at 30 minutes in all 12 control limbs and in the 10 limbs with venous disease, but in only one of the 34 lymphoedematous limbs.The amount of activity present in each ilio-inginal lymph node chain at 30 minutes, estimated as a percentage of the injected activity was significantly lower in the 34 iymphoedematous limbs (0.042% ~ 0.072) than in the 12 control limbs (1.4% ~ 0.7)*.The 10 limbs mi~h venous disease had a significantly higher intake (2.3% ; 0.84)** than the control limbs.The percentage uptake of the colloid in the ilio-inguinal lymph nodes at I, 2 and 3 hours increased with time in both the venous and control limbs while comparison of the control and venous limbs showed that the venous limbs maintained a statistically higher uptake in the lymph nodes at I, 2 and 3 hours.The 34 lymphoedematous limbs showed a persistently low uptake of the colloid throughout the study.On visual interpretation the sensitivity of this technique in diagnosing lymphoedema was 97% and its specificity 100%. Estimation of the percentage uptake of the colloid has demonstrated the slow lymph clearance associated with lympboedema and the increased lymphatic flow that may be associated with venous oedema.The technique differentiates between normal limbs, lymphoedema and venous oedema and can be used as a simple diagnostic outpatient technique in the investigations of chronic limb oedema. In order to assess the clinics] usefuln ass Of quantitative lymphoscintigraphy in pts with limb oedema,the Ketterings' method(1981) was employed with slight mo difications related to the different tr acer(rgmTc-S mierocoll)and device(LFOV camera)used. About imCi in.lml(Lymphoscint Solco)were injected in the ist and 3rd interdigital space bilaterally;45ptswere studied:41 with oedema of different aethiology and 4controls(g).ROIs were selected includi ng the injection site(IS),regional nodes (RN)and the limb region between IS and RN(Transit Activity,TA)respectively. Semiquantitative data were expressed as % of the IS activity measured at T~,TA was normalized to i0 sq cm area. Results:the wash out rate at D h was>20% in 6/8C and<20% in 19/20 limbs with lymp hoedema(L)(p <.Ol).The mean T6 value(t/h) was g 2% in 18/20 L(pd. Ol) We have now used 123Y BSP as a specific hepatocyte la~el to see if this discriminates better between types and severity of liver disorders.Twenty five patients with histologically proven liver disease had 1231 BSP and 99TO sulphur colloid tomography performed on separate days using an IGE 400T camera interfaced to a PDP 11/34 Digital computer.SPET Software produced 3-dimensional reconstruction of images. Total 123[ BSP and 99Tc sulphur colloid uptake values and liver volume were then derived. Patients with severe liver disease had percentage uptakes of: 38.9(~ 8.8) and 20.7( ! 5) for 1231 ESP and 99TO sulphur colloid respectively.Those with moderate disease: 62.8(~ 6.5) and 42(~ 6) and those with minimal dysfunction 76.5(2 12) and 61.6 (~ 14). These values correlate well with the clinical and histological findings.The study demonstrates the feasability of 1231ESP tomography in the assessment of liver disease.The use of both isotopes provides a means of measuring both hepatocyte and Kupffer cell function as well as structure. Portosysfemic shunt is one of the most important complications of Liver cirrhosis. UnfortunateLy, current methods for detecting and quantifying this shunt are either non-specific or associated with significant morbidity. The aim of this work was fo evaluate the cLini-caL value of a new non-traumatic method which consisted of administrating TL-201 per rectum and to monitor the absorbed activity using a camera and a computer system. The method assumes that in the absence of portosystemic shunt, most of the absorbed activity wiLL be fixed in the Liver while in the presence of this shunt,some of the activity wiLL be fixed in the myocardium. The ratio of heart to Liver activity can therefore be used to evaluate the importance of the porfosystemic shunt. 34 subjects have been studied. The ratio of heart to liver activity at the g5th minute after the tracer administration is higher in patients with Liver cirrhosis (n=22, m= .9, s.d.-.37) than in patients with steatosis. (n-t0, m= .28, s.d.= .05). In two healthy subjects investigated the H/L ratio was .27 and .30. The reproducibiLity of the test was evaLuated in 8 subjects and showed a good reproducibility. (mean of difference = .03, range = .01 fo .07). Patients with esophageal varices had always a high H/L ratio white some patients with Liver cirrhosis without esophageal varices had also high H/L ratio due probably to the presence of infrahepatic shunt. In conclusion, our results showed the value of this new non-traumatic test for detecting and quantifying extra-as weLL as intrahepafic portosystemic shunt. Ill-In-labelled autologous l~latelets were applied for scintigraphic localization of the source of gastrointestinal bleeding. 29 investigations were performed in 25 patients. In 19 studies showing scintigraphic signs of bleeding, the clinical presentation included occult bleeding in 7, melaena in 7, and bloody stools in 5. The time interval between the injection of lll-In-platelets and visualization of bleeding rangad from i0 rain to 142 h, being longest in cases of occult bleeding. In most cases, the scintigrapbic findings were supported by other diagnostic modalities. In l0 studies, without signs of bleeding, a probable source of bleeding was identified in one patient. Difficulties in reaching firm conclusions on delayed scintigran%s because of accelerated transit of the intestinal contents were encountered in a few cases. To circumvent this problem, we introduced a combined scintigraphic approach by adding a sequential 99m-Tc sulfur colloid study at the time an abnormality on the lll-In-platelet scintigram was first noticed. Using this approach, we could pin-point the source of bleeding in the 5 studies carried out. Our findings indicate that the lll-In-platelet method is sensitive, a fact probably related to the low level of background activity, to the incorporation of labelled platelets in the clot formed at the site of bleeding, and to the possibility of repeated imaging for up to one week after the tracer injection. It may prove of special usefulness in cases of OCCUlt or recurrent bleeding. and Surgical Gastroenterology, Odense University Hospital, DK-5000 Odense C, Derm~aZk.