Carotid atherosclerotic plaque: Noninvasive MR characterization and identification of vulnerable lesions

Measurement of vessel stenosis by using ultrasonography or angiography rema ins the principal method for determining the severity of carotid atheroscle rosis and the need for endarterectomy. The ipsilateral stroke rate, however -even in patients with severely stenotic vessels-is relatively low, which s uggests that the amount of luminal narrowing may not represent the optimal means of assessing clinical risk. As a result, some patients may undergo un necessary surgery. Improved imaging techniques are, therefore, needed to en able reliable identification of high-risk plaques that lead to cerebrovascu lar events. High-spatial-resolution magnetic resonance (MR) imaging has bee n described as one promising modality for this purpose, because the techniq ue allows direct visualization of diseased vessel wall and can be used to c haracterize the morphology of individual atherosclerotic carotid plaques. T he purpose of this report is to review the current state of carotid plaque MR imaging and the use of carotid MR to evaluate plaque morphology and comp osition.