Computed angiotomography of the brain: normal and normal variations of cerebral vessels.

Computed angiotomography with intravenous minimum dose bolus injection of contrast medium permits identification of the circle of Willis and the basal cerebral veins. The normal and normal variations of these vessels in the various clinical cases are presented and described in relation to other neighbouring structures. A detailed knowledge of computed angiotomographic images of normal cerebral vessels can serve as a clinical basis for evaluating the cerebrovascular lesions.