Chest CT versus RT-PCR for the Detection of COVID-19: Systematic Review and Meta-Analysis

Karam, M.; Althuwaikh, S.; Alazemi, M.; Abul, A.; Hayre, A.; Gavin, B.

Objectives To compare the performance of chest computed tomography (CT) scan versus reverse transcription polymerase chain reaction (RT-PCR) in the initial diagnostic assessment of coronavirus disease 2019 (COVID-19) patients. Methods A systematic review and meta-analysis were performed as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. A search of electronic information was conducted to identify studies comparing the diagnostic performance within the same patient cohort of chest CT scan versus RT-PCR in COVID-19 suspected cases. Sensitivity, specificity and accuracy were primary outcome measures. Secondary outcomes included other test performance characteristics, discrepant findings between both investigations and main chest CT findings. Random effects modelling was used for the analyses. Results Thirteen non-randomised studies enrolling 4092 patients were identified. Accuracy was statistically significantly higher for RT-PCR versus chest CT (Odds Ratio [OR] = 0.22, P = 0.001). Chest CT is also less specific than RT-PCR. Ground-glass opacities and consolidations were the most common chest CT manifestations. Importantly, early small studies tended to favour chest CT versus later larger studies. Conclusion Chest CT is inferior to RT-PCR for the initial detection of COVID-19 and has more false positives. It may still be useful in confirming COVID-19, however, in patients with a suspicious clinical presentation, but who have a false-negative SARS-CoV-2 RT-PCR test.