Solution: Right sided aortic arch is associated with at least high potential configurations. The two that are most common are the right sided arch with an aberrant left subclavian (low, 10% incidence of associated CHD) as is seen here, and a right sided aortic arch with mirror image branching (High >90% association with CHD, especially TOF). In this case, it is an incidental and clinically unimportant finding. It is the 2nd most common vascular ring after double aortic arch. The bulbous configuration at the origin of the left subclavian artery is known as a diverticulum of Kommerell.