Bronchial Diverticula in Smokers on Thin-section CT

Purpose of the Study: To determine the prevalence of bronchial diverticula in smokers on thin-section CT and their relationship to clinical and other morphologic features on CT. Methods: Thin-section CT axial images of 503 heavy smokers were reviewed and coronal and sagittal/oblique reformations obtained to assess the location and the extent of the diverticula in the major airways. The bronchial diverticula extent was recorded using a three point scale: grade 0, none; grade 1, 1 to 3 diverticula; grade 2, >3 diverticula. The extent of emphysema, severity of intraparenchymal bronchial wall thickness, clinical features were compared between sub-groups stratified according to the bronchial diverticula extent score. Results: 229 (45.5%) out of 503 smokers had bronchial diverticula, with 168/503 (33.3%) and 61/503 (12.2%) showing grade 1- and 2-bronchial diverticula, respectively. Subjects with grade 2-bronchial diverticula were heavier smokers, reported a history of cough more frequently, and showed more severe functional impairment, greater emphysema extent on CT and more severe bronchial wall thickening, as compared to both subjects with grade 1- and those individuals without bronchial diverticula (P <0.0001). Multivariate regression analysis revealed that intra-parenchymal bronchial wall thickness [grade 1- (odds ratio 1.23) and grade 2- bronchial diverticula (odds ratio 1.78) compared to individuals with no diverticula] and the extent of emphysema [grade 1- (odds ratio 1.06)] predicted the bronchial diverticula extent.