MR angiography in cases with vertebrobasilar artery insufficiency

MR angiography (MRA) was performed on 18 patients suspected of having Vertebro-basilar Artery Insufficiency (VBI). Eight of them (44%) showed abnormal findings such as a narrowing of the vertebral or basilar artery either with or without an enhanced Posterior communicating artery (P-COM), an aneurysm on the superior cerebellar artery and occlusion of the unilateral internal carotid artery. An enhancement of the P-COM might thus induce an increased blood flow as a collateral vessel in VBI. These cases all demonstrated either unilateral hearing loss or canal paresis on the sides of the narrowed vertebral artery. We also discuss the diagnostic value of MRA for VBI. (author)