Pulmonary aplasia: MR angiography findings.

A 26-year-old woman presented with absence of the left lung. A diagnosis of pulmonary aplasia (main bronchus ending in a blind pouch) was established by bronchoscopy. Although a CT scan and MR imaging suggested the correct diagnosis, MR angiography enabled optimal demonstration of the vascular changes due to the anomaly (single main pulmonary artery and vein) and an associated anomaly (azygous continuation of the inferior vena cava).