Color-flow Doppler and conventional duplex scanning of the carotid bifurcation: prospective, double-blind, correlative study.

Color-flow Doppler is a useful adjunct in duplex sonography of peripheral vessels. This study was undertaken to see if color-flow Doppler could give semiquantitative information about the degree of stenosis at the origin of the internal carotid artery. The factors evaluated on color flow are the width of the lumen as estimated from the color-flow image relative to the width of the vessel, the degree of turbulence (evidenced by the mosaic pattern), and the pulse-repetition frequency necessary to prevent aliasing. A double-blind comparison with conventional duplex scanning in 146 carotid bifurcations in 74 patients was carried out. In 91%, the color-flow assessment was in complete agreement with the duplex assessment. In the remaining 9%, the color flow differed from the duplex by only one stenosis group, and the distributions of over- and under-estimation were equal. These results showed comparable assessment of the degree of stenosis with conventional duplex and color Doppler technology.