Peripheral arterial Doppler ultrasonography: diagnostic criteria.

Fifty-one patients (86 legs) were studied from the aorta to the popliteal artery with both duplex ultrasonography and arteriography with the intention of establishing diagnostic ultrasonographic criteria for degrees of stenosis greater than 50% and determining the effect of multi-segment disease on the accuracy of these criteria. Receiver operator characteristic curves were used to determine diagnostic criteria for greater than 50%, greater than 70%, greater than 90% diameter stenoses or occlusions. A stenosis of greater than 70% was diagnosed either if the peak systolic velocity was more than 160 cm/sec (sensitivity 77%, specificity 90%) of if there was an increase in peak systolic velocity of 100% with respect to the arterial segment above the stenosis (sensitivity 80%, specificity 93%). Sequential stenoses were detected with lesser sensitivities. Ratio criteria were more accurate than peak systolic velocity for all degrees of stenosis. For detection of occlusion, duplex ultrasonography was 92% sensitive and 99% specific.