1Merck Research Laboratories,
Patients with carotid plaque undergo endarterectomy based on empirical guidelines, primarily the magnitude of stenosis. Patients who would derive benefit from carotid endarterectomy are those with lipid rich, vulnerable plaque at high risk of rupture. We hypothesis that non-invasive MRI technique can provide distinguishable signal features of plaque components such as fibrous tissue, lipid-rich necrotic core, intra-plaque hemorrhages, and calcifications, therefore can help identify at-risk patients preoperatively. The purpose of this study is to demonstrate the capability of MRI and MRS methods for characterizing plaque composition and quantifying lipid deposition, thereby facilitating development of noninvasive, quantitative predictor of plaque stability.