| Popis: |
Forty-six consecutive studies of carotid bifurcations were done with a Hokanson Ultrasonic Arteriograph before contrast arteriography. Based on the Doppler signal and the oscilloscopic image, each internal carotid artery was sorted into one of four categories as an estimation of the percent diameter reduction: less than or equal to 10 percent, 10 percent to 49 percent, 50 percent to 99 percent, and total occlusion. These results were compared with the percent diameter reduction determined from contrast arteriograms by a vascular radiologist unaware of the noninvasive test results. Overall, 83 percent of the arteries were correctly categorized. Detection of stenosis in the 50 percent to 99 percent range was 89 percent accurate. The sensitivity and specificity in detecting a 50 percent or greater stenosis were both 96 percent. |
