title: Radiographic Differentiation of Advanced Fibrocystic Lung Diseases.
abstract: The concept of end-stage lung disease suggests a final common pathway for most diffuse parenchymal lung diseases. In accordance with this concept, end-stage disease is characterized radiographically and pathologically by the presence of extensive honeycombing. However, sequential computed tomographic (CT) scans obtained from patients with chronic diffuse lung disease evolve over time to show various advanced lung disease patterns other than honeycombing. In addition, several radiographically distinct honeycomb patterns, including microcystic, macrocystic, mixed, and combined emphysema and honeycombing, differentiate one advanced lung disease from another. For example, usual interstitial pneumonia (IP) usually shows mixed microcystic and macrocystic honeycombing. In contrast, CT images of long-standing fibrotic nonspecific IP typically show only small, scattered foci of honeycombing; instead, most enlarged airspaces observed in the advanced stage of this disease represent dilatation of bronchioles. In desquamative IP and pulmonary Langerhans cell histiocytosis, focal opacities typically evolve into emphysema-like lesions seen on CT imaging. In combined pulmonary fibrosis and emphysema and sarcoidosis, the cysts tend to be larger than those observed in usual IP. Sequential CT scans in other chronic, diffuse lung diseases also show various distinctive changes. This article highlights radiographic patterns of lung destruction that belie a single common pathway to end-stage lung disease. Recognition of distinct radiographic patterns of lung destruction can help differentiate diffuse parenchymal lung diseases, even in advanced stages of disease evolution.
authors.affiliation: Department of Radiology, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai City, Osaka, Japan.
authors.forename: Masanori
authors.identifier: http://orcid.org/0000-0002-4097-8105
authors.initials: M
authors.lastname: Akira
mesh_terms: D003937:Diagnosis, Differential; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000000981:diagnostic imaging; D008168:Lung / Q000000981:diagnostic imaging*; D017563:Lung Diseases, Interstitial / Q000150:complications / Q000000981:diagnostic imaging*; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed
keywords: diffuse parenchymal lung disease; end-stage lung; high-resolution computed tomography; honeycombing; interstitial lung diseases