Validity of continuous-wave Doppler sonography of the vertebrobasilar system.

To assess the value of continuous-wave Doppler sonography for detection and exclusion of lesions in the vertebrobasilar system, the ultrasonic and angiographic findings were compared in a prospective study. Altogether, 200 vertebral arteries in 176 patients were evaluated by both methods. Insonation of the vertebral arteries was performed at the mastoid slope and at the origin of the vessel. Of 62 angiographically proven lesions, 45 were detected by ultrasound. Of 138 normal vertebral arteries, 129 were correctly diagnosed. Sensitivity for all lesions was 72.5%, and for hemodynamically relevant lesions it was 91%. Overall specificity was 93.5%. A positive predictive value of 83.3% and a negative predictive value of 88.4% for all lesions shown by angiography demonstrate the high reliability and accuracy of doppler ultrasound of the vertebrobasilar system.