[MRI findings in patients with vertigo and dizziness possibly arising from vertebrobasilar insufficiency].

In order to evaluate diagnostic usefulness of MRI in vertebrobasilar insufficiency (VBI), we performed magnetic resonance imaging (MRI) and MR angiography (MRA) in 90 patients presenting vertigo and dizziness as an initial and cardinal complaint. High signals observed by T2-weighted imaging in the basal ganglia (44.4%) or pontine base (48.9%) were more frequently seen in the possible VBI group than in the controls (p < 0.001). The electronystagmographical abnormalities were commonly observed in the patients with a high signal in the pontine base, reflecting diffuse ischemic lesion in the territory of the vertebrobasilar system. Vertebral artery asymmetry (45.6%) or basilar artery twisting (41.1%) as shown by MRA was also significantly more frequent in the patients than in the controls (p < 0.05). In conclusion, MRI and MRA were considered to be useful in making a clinical diagnosis of VBI in such patients.