Stroke. Coloured axial magnetic resonance imaging (MRI) scan through the brain of a 54-year-old woman who has had a stroke (black area at upper centre) in the left side of her brain. This stroke (also called a cerebrovascular accident, CVA) is due to a blockage (occlusion) of the cerebral arteries, with the left internal carotid artery in the neck shown at right. This is a T2 sequence MRI, with inversion used to highlight the tissues being examined.