The results of continuous wave Doppler scanning of 96 common carotid arteries and their immediate branches were compared with those of selective angiography. The overall accuracy of the Doppler technique for the assessment of the common, internal and external carotid arteries was 98%, 81% and 86%, respectively with a sensitivity of 60%, 70% and 54%, and a specificity of 100%, 93%, and 96%. When stenoses of 50% were considered hemodynamically insignificant, the overall accuracy of the assessment of the common, internal and external carotid arteries rose to 100%, 93% and 93%, but the sensitivity was only 100%, 83% and 53%, whereas the specificity was 100%, 96% and 96%. This modality did not prove useful in the detection of intimal ulcers and plaques nor could the degree of stenosis be accurately graded. The above data indicate that contrast angiography remains imperative prior to surgery.
