MRI diagnosis of isolated origin of the left subclavian artery from the left pulmonary artery.

Right aortic arch with isolation of the left subclavian artery is a rare disorder. In this entity, the left subclavian artery has its origin from the pulmonary artery via the ductus arteriosus. We report an infant with an unbalanced atrioventricular septal defect, right aortic arch, bilateral ductus arteriosi and an isolated left subclavian artery. This infant also had chromosome 22q11 deletion. The origin and course of the isolated subclavian artery were well-demonstrated using contrast-enhanced 3-D magnetic resonance angiography. This non-invasive diagnostic modality can accurately reveal detailed mediastinal vascular anatomy in a young infant and allows diagnosis of aberrant vascular connections.