The cerebral and vertebrobasilar arteries supply regions of the brain in a predictable distribution
Different areas of the brain are supplied by the anterior, middle and posterior cerebral arteries in a predictable distribution. The posterior fossa structures are supplied by the vertebrobasilar arteries.
The arteries of the brain are not well visualised on conventional CT, but a knowledge of the areas of the brain they supply is helpful in determining the source of a vascular insult.