[Interstitial Lung Abnormalities (ILAs) in the post-COVID-19 era: A call for increased radiologist awareness]

Interstitial lung abnormalities (ILAs) are incidental radiological findings characterized by lung parenchymal changes affecting at least 5% of the lung in asymptomatic individuals. The COVID-19 pandemic raised concerns regarding post-viral lung damage contributing to ILA and its potential progression to pulmonary fibrosis. This study aimed atassessing the prevalence and characteristics of ILAs in the post-COVID-19 era and at exploring potential associations with fibrosing evolution.

The authors retrospectively analyzed, from January 2023 to January 2024, 343 chest CT scans from patients over forty years old without previous diagnosis of interstitial lung disease (ILD). Based on the Fleischner Society criteria, ILAs were divided into three subtypes : non-subpleural ILA, subpleural non-fibrosing ILA, and subpleural fibrosing ILA. In their interpretations of scan results, the authors described a number of elementary ILA lesions, including ground-glass opacities, lung reticulation, septal thickening, traction bronchiectasis, cysts, honeycomb appearance and architectural distortion.

The results indicated overall ILA prevalence of 18%, with subpleural fibrosing and non-fibrosing ILAs each accounting for 8%, and non-subpleural ILAs for 2%. Female predominance was observed, with an average age of 59 years. Compared to pre-pandemic studies, which reported overall prevalence approximating 7% in the overall population, these findings suggest increased prevalence of fibrosing ILA, potentially linked to post-COVID lung changes.

Heightened risk prevalence of fibrosing ILAS in the post-COVID-19 era raises questions concerning the underlying mechanisms of pulmonary remodeling and its potential for evolving toward diffuse interstitial lung disease. Longitudinal monitoring is called for, the objective being to assess possible progress in view of developing appropriate follow-up strategies, during which radiologists are to assume a critical role in early detection and risk stratification. Future research should consider SARS-CoV-2 infection along with age, smoking status and family history of pulmonary fibrosis as a potential risk factor for ILA, with emphasis laid on long-term follow-up and a potential need for revised monitoring protocols in post-COVID patients.