The diagnostic accuracy of ex vivo MRI for human atherosclerotic plaque characterization

Recent evidence indicates that the type of atherosclerotic plaque, rather t han the degree of obstruction to flow, is an important determinant of the r isk of cardiovascular complications. In previous work, the feasibility of u sing MRI for the characterization of plaque components was shown, This stud y extends the previous work to all the plaque components and shows the accu racy of this method. Twenty-two human carotid endarterectomy specimens unde rwent ex vivo MRI and histopathological examination. Sixty-six cross sectio ns were matched between MRI and histopathology. In each cross section, the presence or absence of plaque components were prospectively identified on t he MRI images. The overall sensitivity and specificity for each tissue comp onent were very high, Calcification and fibrocellular tissue were readily i dentified. Lipid core was also identifiable. However, thrombus was the plaq ue component for which MRI had the lowest sensitivity. A semiautomated algo rithm was created to identify all major atherosclerotic plaque components. MRI can characterize carotid artery plaques with a high level of sensitivit y and specificity. Application of these results in the clinical setting may be feasible in the near future.