[Evaluation and clinical management of interstitial lung abnormalities : Position paper of the Austrian Society of Pneumology (ÖGP) and the Austrian Radiological Society (ÖRG) 2026].

Interstitial lung abnormalities (ILA) are findings detected on computed tomography (CT) that potentially reflect early stages of interstitial lung disease (ILD). Their prevalence ranges between 3-10% in the general population, with higher rates observed in older individuals and smokers. ILA include bilateral and nonhypostasis-related ground-glass opacities, reticular abnormalities, traction bronchiectasis, lung architectural distortion and honeycombing, affecting more than 5% of a lung zone. The risk of progression to ILD varies between 20-80%, depending on the ILA subtype and associated risk factors. Clinical progression and risk factors include advanced age, nicotine exposure, inhaled noxious substances, thoracic surgical procedures, pneumotoxic treatment and abnormal pulmonary function parameters. Radiologically, fibrotic ILA with subpleural and basal predominance as well as larger extent of lung involvement are significantly associated with increased risk of progression. The clinical management is based on a structured evaluation including high-resolution CT, lung function diagnostics and risk stratification. In the absence of signs of advanced fibrotic changes, individualized follow-up intervals ranging from 6-36 months are recommended, depending on the patient's risk profile. This position paper provides practical recommendations for managing ILA, in line with current international guidelines, while considering new evidence on genetic risk factors, imaging features associated with progression and clinical predictors. The aim is an early identification of high-risk patients and avoidance of unnecessary diagnostic or therapeutic interventions.