Carotid artery disease: new criteria for evaluation by sonographic duplex scanning.

Use of established criteria in duplex sonographic screening for internal carotid artery disease resulted in low sensitivity (52%) and efficiency (82%). Analysis of duplex velocity data in 51 patients (102 vessels) led to the development of two new criteria for significantly diseased vessels: the ratio of the right to left peak systolic average velocities in the common carotid arteries (Vrcca/Vlcca) of less than 0.7 or greater than 1.3, and a peak systolic average velocity in the common carotid artery (Vcca) of less than 25 cm/sec. Addition of these criteria improved our sensitivity and efficiency to 95% and 94%, respectively.