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

## TL;DR

This study found that many patients with post-COVID-19 respiratory symptoms still have lung abnormalities visible on CT scans after 12 months, which are linked to reduced lung function.

## Contribution

The study provides new evidence on the long-term CT and pulmonary function outcomes in post-COVID-19 patients.

## Key findings

- 78.3% of patients showed residual lung abnormalities on CT scans at 12 months.
- Fibrosis-like findings were associated with significantly lower total lung capacity.
- A moderate negative correlation was found between CT scores and total lung capacity.

## Abstract

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.

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.

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).

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.