Role of HRCT in Diagnosing Interstitial Lung Disease (ILD)

Honeycombing must be present for a diagnosis of UIP by HRCT.⁴⁵ Honeycombing can be accompanied by traction bronchiectasis or bronchiolectasis, and is subpleural with basal predominance. Less common features accompanying the UIP diagnosis are ground glass opacification on a reticular background, mediastinal lymphadenopathy, small ossified nodules, and features of pleuroparenchymal fibroelastosis at the lung apices. Here we see significant honeycombing, which can be seen in a predominantly subpleural pattern occurring at the bases of the lung as seen in the coronal image. Peripheral reticulation and traction bronchiectasis are present. Note the asymmetric pattern of fibrosis, a hallmark feature of usual interstitial pneumonia not often seen with NSIP.