Assessment of vessel wall thickness in carotid atherosclerosis using spiral CT angiography.

Objectives: the purpose of this study was to evaluate the amount of vessel wall thickening in the internal and common carotid arteries in patients undergoing spiral CT angiography for the investigation of significant atherosclerotic disease.

Materials And Methods: forty-five carotid systems in patients with a 70% or greater stenosis (according to carotid duplex) were imaged with CT spiral angiography using a standardised protocol. The vessel wall thickness of the distal common and mid internal carotid artery was measured using axial CT sections.

Results: vessel wall thickness was greater and more variable within the common carotid artery than within the internal carotid artery. The mean proportion of total vessel diameter constituted by vessel wall thickness was significantly greater in the common carotid artery as compared to the internal carotid artery: 28+/-12% (SD) vs 15+/-6%, respectively (p < 0.001).

Conclusions: significant and extended wall thickening is commonly present in the internal and common carotid arteries of patients with atherosclerotic disease, but the internal carotid artery is significantly less affected than the common carotid artery. These observations question the validity of using the common carotid artery as a reference vessel for angiographic stenosis measurements.