Incidental pulmonary findings on CT in daily practice: the nodule and the interstitial lung abnormalities - what’s old, what’s new

The growing use of computed tomography (CT) in clinical practice has led to an increase in incidental pulmonary findings, with nodules being among the most commonly encountered. Managing these nodules remains a significant challenge in clinical radiology. In addition to nodules, interstitial lung abnormalities (ILAs) have emerged as a newly defined entity, necessitating recognition to prevent underestimation and misinterpretation, as well as to guide appropriate management. This review aims to examine the interpretation of incidental pulmonary nodules, providing clarity on their management and addressing gaps not covered by the 2017 Fleischner Society Guidelines. Additionally, we focus on recent updates related to ILA classification, as outlined by the Fleischner Society, and highlight key radiologic features critical for distinguishing ILAs from non-ILA alterations. Finally, we explore the potential future developments in the evaluation of ILAs, offering insights into how the radiologists' role in managing these abnormalities may evolve.