CAROTID PLAQUE-FORMATION AND ITS EVALUATION WITH ANGIOGRAPHY, ULTRASOUND, AND MR-ANGIOGRAPHY

The accurate assessment of carotid artery disease is an important chal lenge for magnetic resonance (MR) angiography. Studies indicate that t he detection and grading of stenosis and the evaluation of plaque morp hology are all important steps in the clinical assessment of atheroscl erosis. The prevalence of significant carotid artery stenosis in the e lderly population and even in patients with symptoms of carotid artery disease is low; clinical risk seems to correlate more closely with pl aque morphology and surface characterization than with the degree of s tenosis. This highlights the importance of MR angiography and ultrasou nd, which can help characterize plaque morphology in addition to showi ng the degree of stenosis. The authors review the present understandin g of plaque formation, comparisons of plaque imaging with conventional angiography, ultrasound, and MR angiography, and recent progress in M R angiography techniques. Several studies, including the North America n Symptomatic Carotid Endarterectomy Trial and the European Carotid Su rgery Trial, are discussed regarding the current objectives of carotid artery imaging. The sensitivity and specificity of plaque detection a nd morphologic evaluation continue to improve.