Anomalous left pulmonary artery: two new adult cases.

Two adult cases of anomalous left pulmonary artery (pulmonary artery sling) are described. Findings on plain radiography, conventional pluridirectional tomography, and barium esophagography led to diagnosis. Computed tomography (CT), not previously described in this anomaly, was done in each case, confirming the diagnosis and excluding other mediastinal abnormalities. Pulmonary arteriography was incidentally performed in one patient and was diagnostic. Tracheobronchial anomalies were seen in both cases. The authors suggest the diagnosis of anomalous left pulmonary artery may be made by noninvasive conventional methods and CT without the need for pulmonary arteriography.