Doppler Criteria for Identifying Proximal Vertebral Artery Stenosis of 50% or More

Abstract

OBJECTIVES: The proximal segment of the vertebral artery is a frequent site of obstructive atherosclerosis. The purpose of this study was to determine Doppler criteria for identifying proximal vertebral artery stenosis of 50% or more by comparison with digital subtraction angiography. METHODS: Forty-eight patients with vertebral artery stenosis were examined prospectively with color Doppler sonography and digital subtraction angiography. The peak systolic velocity (PSV), end-diastolic velocity (EDV), peak systolic velocity ratio (PSVr), and end-diastolic velocity ratio (EDVr) were evaluated by receiver operating characteristic curve analysis for their ability to detect vertebral artery stenosis of 50% or more. The optimal criteria for identifying proximal vertebral artery stenosis of 50% or more were determined. RESULTS: For identifying vertebral artery stenosis, the parameter with the highest accuracy was the PSVr (area under the receiver operating characteristic curve, 0.967 [95% confidence interval, 0.899-0.994]). A PSVr of greater than 2.2 was found to be the optimal criterion for identifying proximal vertebral artery stenosis of 50% or more, with sensitivity and specificity of 96% and 89%, respectively. The optimal thresholds for the other Doppler parameters in identifying proximal vertebral artery stenosis of 50% or more were as follows: PSV, greater than 108 cm/s; EDV, greater than 36 cm/s; and EDVr, greater than 1.7. CONCLUSIONS: Color Doppler sonography is an accurate method for identifying proximal vertebral artery stenosis. The PSVr is superior to other Doppler parameters for detecting vertebral artery stenosis.