Right aortic arch and its variants.

A number of congenital anomalies of the aortic arch complex can occur, ranging from asymptomatic normal variations in arch vessel branch pattern to symptomatic vascular rings, stenoses, and arch interruptions with a frequency ranging from 0.5% to 3.0%. A right aortic arch is present in 0.1% of the population and can occur in isolation or be associated with congenital heart disease. Patients may present at any age with signs and symptoms of airway or esophageal compression, heart failure, or abnormal chest imaging studies. This pictorial essay will show the computed tomography and appearances of congenital variations of the right aortic arch and use Edwards' hypothetical embryonic double aortic arch model to explain the cause of some of these variants.