Bronchiectasis.

Bronchiectasis, or the irreversible dilatation of bronchi, can present with a host of nonspecific clinical symptoms, including hemoptysis, cough, and hypoxia. The radiologist, then, can play an important role in its detection and characterization. Bronchiectasis must be differentiated from motion artifact and transient bronchial dilatation in acute lung disease. When diagnosed, a logical approach may allow for proper triage of the patient to prevent progression of disease. The radiologic approach usually begins with CT, which is fast and accurate. The diagnostic approach should be based on the mechanisms of development of bronchiectasis (bronchial wall damage, endobronchial obstruction, and traction) and the location. Once an endobronchial lesion or adjacent fibrosis is excluded, location of the abnormality can be used to help narrow the differential diagnosis. When the bronchiectasis is upper lobe predominant, CF should first be considered but occasionally MAC infection may present with this finding. When the bronchiectasis is mid-upper lobe, then ABPA or chronic hypersensitivity pneumonitis might lead the list of diagnoses. Lower lobe bronchiectasis is usually the sequela of recurrent infection and conditions that predispose to recurrent infections, including Mounier-Kuhn, hypogammaglobulinemia, PCD, and recurrent infections. By using this approach, the radiologist can remain an integral part of the pulmonary team.