Coronavirus Disease 2019 (COVID-19) CT Findings: A Systematic Review and Meta-analysis

Abstract

Purpose: To date, considerable knowledge gaps remain regarding the chest CT imaging features of coronavirus disease 2019 (COVID-19). We performed a systematic review and meta-analysis of results from published studies to date to provide a summary of evidence on detection of COVID-19 by chest CT and the expected CT imaging manifestations.

Methods: Studies were identified by searching PubMed database for articles published between December 2019 and February 2020. Pooled CT positive rate of COVID-19 and pooled incidence of CT imaging findings were estimated using a random-effect model.

Results: A total of 13 studies met inclusion criteria. The pooled positive rate of the CT imaging was 89.76% and 90.35% when only including thin-section chest CT. Typical CT signs were ground glass opacities (83.31%), ground glass opacities with mixed consolidation (58.42%), adjacent pleura thickening (52.46%), interlobular septal thickening (48.46%), and air bronchograms (46.46%). Other CT signs included crazy paving pattern (14.81%), pleural effusion (5.88%), bronchiectasis (5.42%), pericardial effusion (4.55%), and lymphadenopathy (3.38%). The most anatomic distributions were bilateral lung infection (78.2%) and peripheral distribution (76.95%). The incidences were highest in the right lower lobe (87.21%), left lower lobe (81.41%), and bilateral lower lobes (65.22%). The right upper lobe (65.22%), right middle lobe (54.95%), and left upper lobe (69.43%) were also commonly involved. The incidence of bilateral upper lobes was 60.87%. A considerable proportion of patients had three or more lobes involved (70.81%).

Conclusions: The detection of COVID-19 chest CT imaging is very high among symptomatic individuals at high risk, especially using thin-section chest CT. The most common CT features in patients affected by COVID-19 included ground glass opacities and consolidation involving the bilateral lungs in a peripheral distribution.

Keywords: COVID-19; CT imaging findings; ground glass opacities; meta-analysis; thin-section chest CT.

Fig 1

Baseline CT images (a-d) of a 50 year-old man admitted for symptoms of fever for 1 day: there were multiple patchy ground-glass opacities in the left upper lobe and right lower lobe (a, b). Air bronchogram and crazy paving pattern can be seen (c). Lesions are located in the peripheral area of the lung (d).

Fig 2

Flowchart on the article selection process.

Fig 3

Forest plot of the studies for abnormal CT among presumed coronavirus disease 2019 infection. CI = confidence interval; ES = effect size.

Fig 4

Forest plot of the studies for CT findings (GGO, consolidation, GGO with mixed consolidation). CI = confidence interval; ES = effect size; GGO = ground-glass opacities.