Radiologic patterns of interstitial lung disease: a pictorial review based on the 2025 European Respiratory Society/American Thoracic Society Classification

Interstitial lung diseases (ILDs) are a heterogeneous group of diffuse parenchymal disorders with overlapping clinical and physiological features, making imaging central to diagnosis and management. Thin-slice computed tomography (CT) enables recognition of characteristic patterns and disease monitoring, serving as a cornerstone of multidisciplinary discussion. The 2025 European Respiratory Society/American Thoracic Society classification introduces refinements to the 2013 framework, grouping ILDs into three categories: interstitial patterns, alveolar filling disorders, and rare or unclassified disorders. This pictorial essay illustrates the updated classification with representative CT examples.