Ultrasound velocity criteria for vertebral origin stenosis.

BACKGROUND: Despite remaining an important cause of posterior circulation stroke, the non-invasive diagnosis of vertebral artery origin (VAo) stenosis is problematic. We here examine peak systolic velocity (PSV) criteria for the diagnosis of VAo stenosis and assess if the PSV ratio at the origin to the distal segments improves diagnostic accuracy. METHODS: We performed a retrospective analysis of patients studied by catheter cerebral angiography and extracranial Duplex ultrasonography. The angiographic degree of stenosis, PSV at the VAo, proximal vertebral artery (VA1), and intra-foraminal (VA2) segment were recorded. We calculated the VAo/VA1 and VAo/VA2 PSV ratio. A receiver operator curve was obtained (ROC) and the area under the curve (AUC) was compared for three different diagnostic criteria: PSV VAo, VAo/VA1, and VAo/VA2 PSV ratio. RESULTS: A total of 386 vertebral arteries were angiographically examined and VAo stenosis 50-99% was found in 36 (9%) vessels. The PSV VAo was the most accurate diagnostic parameter with an AUC .821 +/- .052 (SE) (CI: .72, .92). A PSV of 114 cm/second maximized sensitivity (71%) and specificity (90%). CONCLUSION: Our results support the use of PSV as a diagnostic criterion for VAo stenosis compared to a PSV ratio of VAo/V1 and VAo/V2