key: cord-1052303-gqlk069n authors: Burger, Irene A.; Niemann, Tilo; Patriki, Dimitri; Fontana, François; Beer, Jürg-Hans title: Lung perfusion [(99m)Tc]-MAA SPECT/CT to rule out pulmonary embolism in COVID-19 patients with contraindications for iodine contrast date: 2020-05-25 journal: Eur J Nucl Med Mol Imaging DOI: 10.1007/s00259-020-04862-3 sha: 5b783e2a072eb019922c497887c9ca4bf16490ce doc_id: 1052303 cord_uid: gqlk069n nan In patients suffering from 2019 novel coronavirus disease (COVID-19) and associated pulmonary infiltrates, pulmonary embolism (PE) represents a differential diagnosis which could alter therapy [1] . The gold standard to rule out significant PE in patients with COVID-19 pneumonia is a contrast-enhanced CT-scan (ceCT) [2, 3] . In patients with contraindications for iodinated contrast-media, perfusion single-photon emission tomography (SPECT) using [ 99m Tc]-labeled-macroaggregated albumin (MAA) could be an alternative. We present a 59-year-old female patient, with high fever and respiratory symptoms since 1 week. A swab test was COVID-19 positive, matching typical mild ground-glass infiltration on an unenhanced CT scan (Fig. 1a) , with a CT-based total severity score (TSS) of 4 [4] . The initial D-dimer was 935 μg/l. Supportive therapy and prophylactic anticoagulation was initiated. Although she reported clinical improvement, oxygen demand increased after 6 days. Ruling out PE with ceCT was not possible due to known severe anaphylactic reactions in the past despite premedication. A SPECT/CT with 180 MBq [ 99m Tc]-MAA was acquired. Despite large wedgeshaped perfusion defects on SPECT (Fig. 1 b) the scan ruled out significant PE, given that all perfusion defects correlated with pulmonary infiltrates or consolidations in the CT lung window, which would result in ventilation defects on V/Q-scans (Fig. 1c, d) , as further explained in the accompanying editorial [5] . The TSS for the second CT was 12, compatible with severe to critical disease [4] . Three days later, the D-dimer dropped to 4 0 9 μ g / l w i t h o u t i n i t i a t i o n o f t h e r a p e u t i c anticoagulation. Respiratory distress increased, indicating invasive ventilation. After 5 days of invasive ventilation, the pulmonary capacity started to improve again, and the patient recovered. Competing interests The authors declare that they have no competing interests. Ethics approval Not applicable. Informed consent General consent for case publication was given by patient. ISTH interim guidance on recognition and management of coagulopathy in COVID-19 COVID-19 complicated by acute pulmonary embolism Acute pulmonary embolism and COVID-19 pneumonia: a random association? CT image visual quantitative evaluation and clinical classification of coronavirus disease (COVID-19) Is there a role for lung perfusion [99mTc]-MAA SPECT/CT to rule out pulmonary embolism in COVID-19 patients with contraindications for iodine contrast?