Azygos continuation of the inferior vena cava: demonstration by NMR imaging.

Azygos continuation of the inferior vena cava was diagnosed by magnetic resonance (MR) imaging in a patient with a right tracheobronchial angle mass. The characteristic findings included a dilated azygos vein and absence of the hepatic segment of the inferior vena cava. Advantages of MR imaging in evaluation of anomalies of the cava are discussed.