The radiologist should be aware of subclavian steal phenomenon as a congenital condition in all patients with a right aortic arch and carefully study the brachiocephalic branching patterns.The affected subclavian artery does not fill from the aorta and only in subsequent frames is there visualization of the distal portion by way of the ipsilateral vertebral artery, or in rare occasions through other cervical collateral pathways.2In tetralogy of Fallot, the diagnosis can be achieved with right ventriculography as well, although selective proximal thoracic aortography would be preferable.