Diameter-based measurements of the degree of carotid artery stenosis using ultrasonography.

Flow velocity measurement by duplex ultrasonography (DUS) is widely accepted as a preoperative method for grading carotid stenoses. Diameter-based grading is used for angiographic methods, but so far the experience is limited regarding diameter-based grading using DUS. In 101 cases with different degrees of carotid stenoses, we compared diameter- and velocity-based grading using DUS and evaluated variability and reproducibility for diameter measurements in 38 of the stenoses.