Imaging Spectrum of Childhood Interstitial Lung Diseases: Focus on Disorders Not Specific to Infancy.

Childhood interstitial lung disease (chILD) comprises a diverse group of rare disorders, which were previously poorly categorized on clinical, histologic, and pathogenic grounds. The classification of chILD introduced by the chILD Research Network has led to a systematic approach to identifying and categorizing these rare conditions. A multidisciplinary approach integrating clinical, radiologic, pathologic, and genetic findings enables accurate diagnosis in children with "pediatric interstitial pneumonia of uncertain cause." It has become apparent that chILDs are collectively frequent in pediatric practice, and prompt diagnosis can improve the outcomes of affected children. Since the clinical symptoms of chILDs are nonspecific, imaging using high-resolution CT plays a central role in the diagnostic approach to this diverse group of diseases. In most disorders, cellular infiltration and abnormal exudates commonly cause acute-phase imaging findings, such as centrilobular ground-glass opacities that are multifocal, geographic, and diffuse, as well as a crazy-paving appearance. Persistent inflammatory reactions lead to chronic-phase findings, including reticulation, lung cysts, and honeycombing with traction bronchiectasis. Small-airway compromise causes air trapping and a mosaic attenuation pattern. These imaging findings are individually nonspecific; however, meticulous integration of the diverse imaging findings allows a specific diagnosis to be reached. The authors review the current knowledge on the imaging findings associated with chILDs based on recent investigations of these conditions. ©RSNA, 2026 Supplemental material is available for this article.