To determine criteria for evaluating the vertebrobasilar arterial system (VAS) by magnetic resonance angiography (MRA), we examined 43 vertiginous cases by MRA. We divided those cases into two groups, the vertebrobasilar insufficiency (VBI) group and the non-VBI group according to clinical diagnoses. MRA results were assessed based on the severity of stenotic changes in the three major VAS arteries, the bilateral vertebral arteries and the basilar artery. The MRA score was defined as the total score of those three arteries in each case, and the severity score was classified in 3 stages (1:ir-regularity, 2:stenosis, 3:interruption). Then we statistically analyzed the correlation between the MRA score and patient's age, between the MRA score and whether a patient has any complications connected with arterial sclerosis or not, and between the MRA score and clinical diagnoses. On statistical analyses, there was no correlation between the MRA score and patient age, or between the MRA score and complications. However, the MRA scores of the VBI group were significantly higher than those of the non-VBI group. These findings indicate that evaluation of stenotic changes in the VAS by MRA might provide useful information for diagnosing VBI.
