Chest, neck and head arteries. Magnetic resonance angiography (MRA) scan of a normal carotid system of a 41 year old woman. Bottom centre is the aortic arch, which curves over the heart. The arteries that branch off from these are: the brachiocephalic artery (right), the left common carotid artery (centre) and the left subclavian artery (left). The brachiocephalic artery splits again into the right common carotid and right subclavian arteries. The right and left common carotid arteries supply the neck and the right and left subclavian arteries supply the arms. MRA is a non-invasive technique to image blood vessels in the body that uses a combination of a very strong magnetic field and radiofrequency (RF) pulses to image the flowing blood.