Cerebral arteriovenous malformation. Coloured 3D computed tomography (CT) scan and angiogram, highlighting the blood vessels in and around the base of the brain of a 38-year-old man. The bulge (red) at upper left is a cerebral arteriovenous malformation (AVM), an abnormal blood vessel arrangement. This was discovered when the patient was hospitalised following a cerebrovascular emergency. This AVM is supplied by collateral branches of the middle cerebral artery. This is a frontal (anterior) view of the blood vessels. For the same view, with the head included, see image C033/7486.