Duplex scanning versus conventional arteriography for the evaluation of carotid artery plaque morphology

Examinations that are performed for the evaluation of the extracranial cerebrovascular system need to supply accurate information regarding the luminal surface of the carotid artery as well as the morphologic characteristics of the plaque. To compare conventional carotid artery angiography and Duplex scanning, 32 consecutive patients underwent both evaluations, the results of which were compared, in a blinded manner, to the plaque characteristics noted on direct examination by the attending surgeon and pathologist. The following observations were made: angiographic and Duplex scanning evaluations concurred with direct-specimen examination for luminal narrowing in 31 of 32 patients (97%) and 30 of 32 patients (94%), respectively, whereas Duplex scanning was more accurate for diagnosing ulcerative lesions, 13 of 14 patients (93%), than angiography, five of 14 patients (36%) (p less than 0.0001). Luminal surface irregularity was accurately described by Duplex scanning in 20 of 23 patients (87%) and by angiography in 11 of 23 patients (48%) (p less than 0.005), whereas plaque morphology or consistency was not commented on with angiography but was accurately described with Duplex scanning in 12 of 12 patients (100%). This series clearly demonstrates that both angiography and Duplex scanning are extremely accurate for determining the reduction in the diameter of the carotid artery, whereas Duplex scanning is more accurate for detecting important plaque characteristics such as irregularity, ulceration, and composition.