1997 Volume 25 Issue 5 Pages 344-351
The recent development of three-dimensional CT angiography (3D-CTA) allows non-invasive, three-dimensional evaluation of intracranial arteries and veins. However, estimation of normal anatomical variants of intracranial vasculature by 3D-CTA has yet to be reported. We illustrate the usefulness of high-resolution 3D-CTA in the evaluation of the clinical significance of anatomical variations of intracranial arteries and veins. We received 100 consecutively examined 3D-CTAs. Variations of the anterior communicating artery complex were diagnosed in 23% of these cases.
These include fenestration of anterior communicating artery (Acom) in 10, fenestration of proximal anterior cerebral artery (A1) in 2, broad anterior communicating artery in 5, broad attachment of Acom in 4, absence of Acom in 1 and other variations in 3. Fourteen out of 23 were accompanied with cerebral aneurysm. Diagnosis of other arterial variations such as median artery of corpus callosum, azygos anterior cerebral artery were readily possible. As for the vertebro-basilar system, fenestration of proximal basilar artery was detected in 6 cases in which 3 were accompanied with cerebral aneurysm. Primitive trigeminal artery was detected in 1 patient.
Three-dimensional CT angiography was also useful in evaluating variations of intracranial veins.Veins of the skull base, deep cerebral veins, posterior fossa veins as well as major cortical veins and dural sinuses were visualized by means of 3D-CTA. Our preliminary study suggests that 3D-CTA has a potential to be a powerful modality in evaluating anatomical variation of intracranial vasculature.
