Prospective evaluation of the accuracy of duplex scanning with spectral analysis in carotid artery disease.

Prospective evaluation of duplex scanning of the carotid vessels was performed over a 2-year period in 125 consecutive patients (249 vessels) with transient ischaemic attacks or minor stroke. Defining disease as a stenosis of greater than 15% reduction of the vessel diameter, with subgroups of 16-49% stenosis, 50-99% stenosis and occlusion, the sensitivity obtained was 96%, specificity 93% and accuracy 94%. With the use of linear multiregression analyses further subgrouping into 50-75% and 76-99% stenosis was performed. The best predictive variables were, in decreasing order, peak systolic velocity, late diastolic velocity and the difference between peak systolic and late diastolic velocity in the internal carotid artery. The additional periorbital Doppler examination caused a slight improvement in determination coefficient and diagnostic accuracy.