BRONCHIOLITIS IN ADULTS - PATHOLOGY AND IMAGING

The most common high resolution CT (HRCT) findings of bronchiolitis ar e centrilobular nodules and branching linear structures in the seconda ry pulmonary lobules or areas of air trapping. These findings can be h elpful in suggesting the presence of bronchiolitis. However, they are nonspecific because there are overlapping features among various kinds of bronchiolitis. Bronchiolar or peribronchiolar inflammation appears as centrilobular nodule, while bronchiolectasis filled with secretion s manifests with branching linear structure on HRCT. Air trapping is s econdary to bronchiolitis. Proliferative bronchiolitis with the findin gs of patchy areas of consolidation or ground-glass opacity can be dis tinguished from other bronchiolitis. Mineral dust-induced bronchioliti s and peribronchiolar lesions in sarcoidosis present with perilymphati c (centrilobular plus perilobular) micronodules in the secondary pulmo nary lobule. Bronchiolitis in hypersensitivity pneumonia appears with poorly defined centrilobular nodules, associated with ground-glass opa city and air trapping.