Comparison of vertebral artery velocity and flow volume measurements for diagnosis of vertebrobasilar insufficiency using color duplex sonography

INTRODUCTION: The aim of this study was to compare the measurements of vertebral artery (VA) systolic flow velocity and flow volume for diagnosis of vertebrobasilar insufficiency (VBI). MATERIAL AND METHODS: We examined 96 patients who were referred for evaluation of VBI. Net vertebral artery flow volume and mean systolic flow velocity were determined by using color duplex sonography. We had grouped the patients into three according to VA flow volume: group 1 was consisted of patients with severely damped VA flow volume (lower than 120 mL/min), group 2 was consisted of patients with moderately damped VA flow volume (120-200 mL/min), group 3 was consisted of patients with normal VA flow volume (>200 mL/min). The mean systolic flow velocities in each group were compared by one-way ANOVA. RESULTS: Mean VA systolic flow velocities of groups 1, 2 and 3 were 32 +/- 12, 42 +/- 10 and 46 +/- 8 cm/s, respectively. Mean VA systolic flow velocity in group 1 was significantly lower than that of group 2 (P = 0.001). However, there were no significant differences between VA systolic flow velocities in groups 2 and 3 (P = 0.2). CONCLUSIONS: According to our findings, measurement of volume in addition to velocity is more valuable in detection of moderately damped VA flow volumes in diagnosis of VBI.