[Radiologic investigation of vertebrobasilar insufficiency and quantification of vertebrobasilar flow with magnetic resonance imaging].

Purpose: To evaluate the contribution of cervical spine radiograms, Doppler US, cervical and cranial MRI, MRA and two dimensional quantification flow in the diagnosis of vertebrobasilar insufficiency.

Materials And Methods: We prospectively examined 25 patients having signs of vertebrobasilar insufficiency (16 females and 9 males, aged 34 to 74 years) and 25 controls of the same age and sex with MRI, MRA, Doppler US and cervical radiograms. Cervical spine radiograms were evaluated for the presence of degenerative changes, osteophytes and loss of height. The flow velocities of the basilar artery and vertebral arteries were measured with two dimensional quantification flow, using time-velocity graphics achieved by means of a region of interest drawn on transverse sections of the vessels. Posterior circulation in farcts and slow flow in vertebrobasilar system arteries were investigated on brain MR images and the presence of cervical osteophytes, spinal cord compression and the effect of the presence of degenerative changes on vertebral arteries were evaluated on cervical MR images. Paired samples T-test, independent samples T-test, Wilcoxon W, Mann-Whitney U and chi-square tests were used for statistical analysis. The significance level was taken at p below 0.05.

Results: From the statistical analysis, we found that there were more pathologic findings on MRA within the patient group compared with the controls (p = 0.002). The velocities measured by MRI were significantly affected by the presence of unknown bright objects on brain MR images, osteophytes on cervical MR images, loss of height and the presence of osteophytes on radiograms in patients having VBI signs, when compared to the controls. In both groups, the measurements of flow velocity in vertebral arteries by Doppler US did not correlate with the measurements by two dimensional quantification flow.

Conclusion: Among the methods we used in our study, MRA was the most specific in the diagnosis of patients with vertebrobasilar insufficiency. However, two dimensional quantification flow can be used as a noninvasive but indirect method to investigate the influence of several factors on the hemodynamics.