key: cord-0710053-107fnvqo
authors: Chen, Rong; Meng, Qing-tao
title: In reply: Uncertainty in using chest computed tomography in early coronavirus disease (COVID-19)
date: 2020-04-02
journal: Can J Anaesth
DOI: 10.1007/s12630-020-01640-5
sha: 4a8dcc9413315bb86ffe2ce353166f3cc96bbc70
doc_id: 710053
cord_uid: 107fnvqo

nan

The recent letter by Drs Mungmunpuntipantipand Wiwanitkit 1 argues that our report about chest computed tomography (CT) findings in a pregnant woman with coronavirus disease (COVID-19) 2 are inconsistent with ''early'' COVID-19. In doing so, they discourage the consideration of CT findings when ruling out cases of COVID-19. Nevertheless, we think that their concern may have be guided by an incomplete understanding of the COVID-19 epidemic. As of 17 March 2020, more than 50,000 people have been confirmed with COVID-19 in Wuhan. During the period of the most severe increases in COVID-19 cases, the supply of nucleic acid detection kits could not meet the demands of the sharp increase in COVID-19 patients. So the diagnosis of COVID-19 followed the New Coronavirus Pneumonia Prevention and Control Program (fifthedition) A issued by the National Health Commission of China that took ''suspected cases with pneumonia imaging features'' as the clinical diagnosis case standard in Hubei Province. This allowed more COVID-19 patients to receive more timely treatment.

In earlier stages of the disease progression, the changes of chest CT scan were mainly congestion, edema, and exudation. For example, Shi et al. reported that ''COVID-19 manifests with chest CT imaging abnormalities, even in asymptomatic patients, with rapid evolution from focal unilateral to diffuse bilateral ground-glass opacities that progressed to or co-existed with consolidations''. 3 It is worth noting that only a single ground-glass opacity can be seen in some patients at an early stage, and the range significantly increases in the short-term re-examination. 4 When a patient's condition improves, a few fibrous streaks may appear. On the contrary, when the condition is more advanced, diffuse lesions appear in the lungs, and the density of both lungs increases, showing a ''white lung'', which seriously affects the patient's lung function. 4 Importantly, all diagnostic methods have disadvantages. In China, 29.2% of asymptomatic patients who were found to be infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and presented with either no or mild symptoms at the time of diagnosis by real-time reverse-transcriptionpolymerase chain reaction (RT-PCR) test had a normal chest CT scan. 5 In addition, there were also some patients with positive chest CT findings who presented with a negative RT-PCR for SARS-CoV-2. 6 Ai et al. showed that 60-93% of cases had an initial positive CT consistent with COVID-19 prior to (or parallel with) the initial positive RT-PCR results. Forty-two percent (24/ 57) of cases showed improvement in follow-up chest CT scans before the RT-PCR results turned negative. 7 Thus, chest CT may still be considered as one of the primary tools for detecting COVID-19 in epidemic areas.

We therefore still suggest that the combined assessment of CT imaging features with clinical and laboratory findings could facilitate diagnosis of COVID-19 earlier and more accurately. This may also help curb the spread of the COVID-19 pandemic.

Conflicts of interest None.

Editorial responsibility This submission was handled by Dr. Hilary P. Grocott, Editor-in-Chief, Canadian Journal of Anesthesia.

Uncertainty in using chest computed tomography in early coronavirus disease (COVID-19)

Chest computed tomography images of early coronavirus disease (COVID-19)

Radiological findings from 81 patients with COVID-19 pneumonia in Wuhan, China: a descriptive study

Initial CT findings and temporal changes in patients with the novel coronavirus pneumonia (2019-nCoV): a study of 63 patients in Wuhan, China

Clinical characteristics of 24 asymptomatic infections with COVID-19 screened among close contacts in Nanjing

Chest CT for typical 2019-nCoV pneumonia: relationship to negative RT-PCR testing

Correlation of chest CT and RT-PCR testing in coronavirus disease, (COVID-19) in China: a report of 1014 cases

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