CT diagnosis of basilar artery occlusion.

Basilar artery occlusion was diagnosed by high-resolution computed tomography (CT) in 11 cases. The normal basilar artery imaged on plain CT scans has an attenuation value not higher than that of whole blood. If the CT attenuation value of the vessel is higher than that of blood, basilar artery occlusion is probably present. The tentative diagnosis can be confirmed by comparison of the attenuation values on the pre- and postcontrast scans, preferably using multiple slices obtained by multiplane dynamic CT.