Diagnostic accuracy of CT and radiographic findings for novel coronavirus 2019 pneumonia: Systematic review and meta-analysis

Purpose: To evaluate pooled prevalence, sensitivity, and specificity of chest computed tomography (CT) and radiographic findings for novel coronavirus-2019 (COVID-19) pneumonia.

Methods: We performed systematic literature search in PubMed and Embase to identify articles reporting baseline imaging findings of COVID-19 pneumonia. The quality of the articles was assessed using NIH quality assessment tool for case series studies. The pooled prevalence, sensitivity, specificity, and diagnostic odds ratio of imaging findings were calculated.

Results: Fifty-six studies (6007 patients, age, 2.1-70 years, 2887 females, 5762 CT, 396 radiographs,) were included. The mean interval between onset of symptoms and CT acquisition was 1-8 days. On CT, the pooled prevalence of ground glass opacities (GGO), GGO plus consolidation, and consolidation only was 66.9% (95% CI 60.8-72.4%), 44.9% (38.7-51.3%), and 32.1 (23.6-41.9%) respectively. Pooled sensitivity and specificity of GGO on CT was 73% (71%-80%) and 61% (41%-78%), respectively. For GGO plus consolidation and consolidation only, the pooled sensitivities/ specificities were 58% (48%-68%)/ 58% (41%-73%) and 49% (20%-78%)/ 56% (30%-78%), respectively. The pooled prevalence of GGO and consolidation on chest radiograph was 38.7% (22.2%-58.3%) and 46.9% (29.7%-64.9%), respectively. The diagnostic accuracy of radiographic findings could not be assessed due to small number of studies.

Conclusion: GGO on CT has the highest diagnostic performance for COVID-19 pneumonia, followed by GGO plus consolidation and consolidation only. However, the moderate to low sensitivity and specificity suggest that CT should not be used as the primary tool for diagnosis. Chest radiographic abnormalities are seen in half of the patients.