Chest CT Lung Abnormalities 1 Year after COVID-19: A Systematic Review and Meta-Analysis

Background: Radiologic lung sequelae may explain the persistence of respiratory symptoms in post-coronavirus disease (post-COVID-19) condition (long COVID). Purpose: To perform a systematic review and meta-analysis of the prevalence and type of COVID-19 residual lung abnormalities at 1-year chest CT. Materials and Methods: A literature search of PubMed, Web of Science, Embase, and Medline databases was performed for articles published from January 2020 to January 2023. Full-text reports of CT lung sequelae in adults (>= 18 years) with confirmed COVID-19 at 1-year follow-up were included. The prevalence of any residual lung abnormality and type (fibrotic or not) was analyzed according to the Fleischner Society glossary. The meta-analysis included studies with chest CT data assessable in no less than 80% of individuals. A random-effects model was used to estimate pooled prevalence. Multiple subgroup (country, journal category, methodologic quality, study setting, outcomes) and metaregression analyses were performed to identify potential sources of heterogeneity. The I-2 statistics estimated low (25%), moderate (26%-50%), and high (>50%) heterogeneity, and 95% prediction intervals (PIs) were computed to describe the expected estimates range. Results: Of 22 709 records, 21 studies were reviewed (20 prospective, nine from China, and seven in radiology journals). The meta-analysis included 14 studies with chest CT data in 1854 of 2043 individuals (1109 male, 934 female). Estimates of lung sequelae were highly heterogeneous (range, 7.1%-96.7%), with a pooled frequency of 43.5% (I-2 = 94%; 95% PI: 5.9, 90.4). This also applied to single nonfibrotic changes, including ground-glass opacity, consolidations, nodules or masses, parenchymal bands, and reticulations. The prevalence range of fibrotic traction bronchiectasis or bronchiolectasis was 1.6%-25.7% (I-2 = 93%; 95% PI: 0.0, 98.6); honeycombing was unremarkable (range, 0%-1.1%; I-2 = 58%; 95% PI: 0, 60). Lung sequelae were unrelated to any characteristics of interest. Conclusion: The prevalence of COVID-19 lung sequelae at 1-year chest CT is highly heterogeneous among studies. Heterogeneity determinants remain unknown, suggesting caution in data interpretation with no convincing evidence. (c) RSNA, 2023

Automated summary

A systematic review and meta-analysis of 1-year follow-up chest CT scans in post-COVID-19 patients revealed highly heterogeneous prevalence of lung sequelae, with unknown determinants of heterogeneity. Caution should be exercised in interpreting the data.