[Magnetic resonance tomographic diagnosis of vascular processes in the vertebrobasilar system--analysis of 35 of our own cases and a literature review].

35 patients with abnormalities of the vertebrobasilar system were studied via magnetic resonance imaging (11 saccular aneurysms, 10 vascular malformations, 9 basilar arteries with dolichoectasia, 5 thromboses of the vertebral or basilar artery). The two smallest aneurysms of the basilar top had a diameter of 2-3 mm. Most vascular malformations could be differentiated by typical MRT symptoms. All 5 cavernous angiomas were negative in angiography (cryptic). The shape and size of the basilar artery and its relationship to the third ventricle were best demonstrated on coronal slices. Flow-related intraluminal loss of signal allows a differentiation between vascular perfusion and thrombosis already on plain images (partial) thrombosis and artery dissection can be differentiated from flow effects based on identical findings in at least two planes or additional gradient echo images.