Lung CT: Part 2, The interstitial pneumonias--clinical, histologic, and CT manifestations.

OBJECTIVE: The interstitial pneumonias are a group of heterogeneous nonneoplastic lung diseases that may be idiopathic or associated with an underlying abnormality. Although they share some features in common, they also exhibit diverse pulmonary manifestations. Imaging plays an essential role in characterizing this group of disorders and can often suggest the diagnosis, though the final interpretation requires a coordinated effort involving the radiologist, pathologist, and clinician. The purpose of this article is to review the imaging features of the interstitial pneumonias according to their histologic patterns and to provide a brief overview of their clinical presentations.

CONCLUSION: This article reviews the interstitial pneumonias according to their histologic subtypes, including both idiopathic and secondary forms. On completion, the reader should have an improved understanding of the classification of the interstitial pneumonias, associated causes, characteristic imaging features, histologic descriptions, clinical manifestations, and prognoses.