PP56 The Use of Computed Tomography for Detecting COVID-19 Pneumonia: Rapid Evidence Review

Introduction The reverse transcription polymerase chain reaction (RT-PCR) test is the gold standard for detecting coronavirus disease 2019 (COVID-19), but recent studies have reported false negative results for RT-PCR. Consequently, several countries are looking at chest computed tomography (CT) for the diagnostic workup of patients with suspected or probable COVID-19 to inform clinical management. Therefore, this rapid review provides the best available evidence on the use of chest CT for detecting COVID-19 pneumonia. Methods Literature searches were conducted in the PubMed, Cochrane Library, JBI Library, Epistemonikos, and Evidence Aid databases for relevant papers published from 1 December 2019 to 12 June 2020. The search strategy was based on the identified population, concept, and context with respect to the objective of the review. The methodological quality of the seven systematic reviews identified was appraised using the AMSTAR checklist. Results The use of CT as a first-line screening tool for COVID-19 is not beneficial. Nevertheless, for patients with suspected COVID-19 pneumonia who had a false-negative RT-PCR results, cross-checking with CT and a repeated RT-PCR test is essential to avoid misdiagnosis. Chest CT offered high sensitivity for detecting COVID-19 pneumonia among symptomatic individuals, especially in those with severe disease. It was also useful for evaluating the potential complications, disease severity, and progression of COVID-19 pneumonia. The features of CT images differed at the early, intermediate, and late stages of COVID-19 pneumonia, but the most common imaging findings were patchy and ground glass opacities. It was also found that diagnosing COVID-19 in children using CT is challenging. Conclusions Even though chest CT is not useful for primary screening of COVID-19, it is useful for detecting later stage disease and for evaluating patients with COVID-19 pneumonia. For patients with suspected COVID-19 pneumonia and a false negative RT-PCR result, cross-checking with a chest CT and a repeat RT-PCR test is essential to avoid misdiagnosis.