The diagnosis of minor to moderate atherosclerotic lesions in the carotid artery bifurcation by means of spectral broadening combined with the direct detection of flow disturbances using a multi-gate pulsed Doppler system.

The diagnostic accuracy of noninvasive detection of carotid artery lesions with a diameter of less than 50% (minor to moderate) and greater than 50% reduction (severe) with the use of a multi-gate pulsed Doppler system (spectral analysis combined with the detection of flow disturbances) was studied in patients with focal neurological symptoms. Biplane arteriography was used as a reference. For all lesions the diagnostic accuracy (observed agreement), sensitivity and specificity was 88, 92, and 84%, respectively, and 84, 83, and 84%, respectively, when only minor to moderate lesions were considered. Kappa, a chance-corrected measure of agreement, which takes into account the marginal distribution of the data and, hence, may be considered to be a better parameter to describe diagnostic accuracy, was found to be 82.2%. The results in this study compare favorably with those obtained in studies employing duplex techniques (B-mode image combined with single-gate pulsed Doppler) and indicate that minor to moderate carotid artery lesions are detected rather accurately with the use of a multi-gate pulsed Doppler system.