Association between abnormalities on chest computed tomography and pulmonary function in patients with respiratory symptoms at 12 months after COVID-19

Associação de anormalidades na tomografia computadorizada de tórax e comprometimento da função pulmonar em pacientes com sintomas respiratórios 12 meses após COVID-19

Abstract

Objective:  To assess the prevalence and type of residual lung abnormalities on chest computed tomography (CT) and pulmonary function testing (PFT) variables in patients with respiratory symptoms related to post-COVID-19 condition at 12 months of follow-up, and to analyze associations between CT findings and PFT parameters.

Materials and Methods:  The CT findings were evaluated by two radiologists, who calculated semiquantitative CT scores. The PFTs included spirometry, plethysmography, and the diffusing capacity of the lung for carbon monoxide.

Results:  Thirty-seven patients were included in the study. On CT scans of the chest acquired at 12 months of follow-up, 78.3% of the patients exhibited residual abnormalities, including reticular opacities, in 75.7%; traction bronchiectasis/bronchiolectasis, in 43.2%; and fibrosis-like findings, in 43.2%. The mean overall CT score was 9.30 ± 2.59. Patients with fibrosis-like findings had significantly lower total lung capacity (68.6% vs. 80.6% of the predicted value; p = 0.018). A moderate negative correlation was found between the overall CT score and total lung capacity (rs = −0.49; p = 0.003).

Conclusion:  It seems that a significant proportion of patients with respiratory symptoms related to post–COVID-19 condition demonstrate residual lung abnormalities on chest CT at 12 months of follow-up, with a substantial prevalence of fibrosis-like findings. Such abnormalities are associated with restrictive lung disease.

Keywords:
Post-acute COVID-19 syndrome; Tomography, X-ray computed; Pulmonary fibrosis; SARS-CoV-2; COVID-19/complications