title: Imaging of Small Airways Diseases.
abstract: Small airways disease, or bronchiolitis, encompasses many conditions that result in bronchiolar inflammation and/or fibrosis. Bronchioles are distal airways within secondary pulmonary lobules that are only visible on imaging when abnormal. High-resolution computed tomography plays an important role in diagnosing small airways disease. The predominant direct high-resolution computed tomography sign of bronchiolitis includes centrilobular nodules, whereas air trapping is the main indirect finding. This article reviews bronchiolar anatomy, discusses the differential diagnosis for cellular and constrictive bronchiolitis with a focus on key imaging features, and discusses how to distinguish important mimics.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143, USA.
authors.forename: Abigail V
authors.initials: AV
authors.lastname: Berniker
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143, USA. Electronic address: Travis.Henry@ucsf.edu.
authors.forename: Travis S
authors.initials: TS
authors.lastname: Henry
mesh_terms: D055745:Bronchioles / Q000000981:diagnostic imaging*; D001988:Bronchiolitis / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D019317:Evidence-Based Medicine; D006801:Humans; D011856:Radiographic Image Enhancement / Q000379:methods*; D013902:Radiography, Thoracic / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Air trapping; Bronchiolitis; Centrilobular nodules; Constrictive bronchiolitis; High-resolution computed tomography; Small airways diseases; Tree-in-bud