HUMAN CAROTID ARTERIES - CORRELATION OF INTRAVASCULAR US WITH ANGIOGRAPHIC AND HISTOPATHOLOGIC FINDINGS

PURPOSE: To establish the intravascular ultrasound (US) morphology of the arterial wall in various segments of the carotid artery and to eva luate atherosclerotic changes correlated with angiographic and in vitr o histopathologic findings. MATERIALS AND METHODS: A total of 67 carot id arteries were imaged with a 3.5-F, 30-MHz intravascular US catheter : Twenty-four arteries were studied in vivo in 22 patients during neur oendovascular interventional procedures, in situ in 10 cadaveric arter ies, and in vitro in 33 fresh excised arteries. RESULTS: In vivo, none of 10 calcifications and five (29%) of 17 intimal thickenings detecte d at intravascular US were seen at contrast material-enhanced angiogra phy. At intravascular US, the arterial wall morphology was consistentl y three layered in the internal carotid artery above the bulb, either vaguely three layered or homogeneous in the bulb and in the carotid bi furcation, and homogeneous in the majority of common carotid arteries. The medial-adventitial interface was distinct in 21 (88%) of 24 arter ies in vivo. Histopathologic and intravascular US classifications of t he plaque agreed for 31 (82%) of the 38 arterial specimens in vitro. C ONCLUSION: In vivo intravascular US was feasible in carotid arteries w ith mild atherosclerosis and often revealed intimal thickenings and co ncentric plaques in angiographically normal segments.