Abstract WP218: Assessment of Carotid Plaque Vulnerability Using Quantitative Expansive Remodeling Evaluation and MRI Plaque Signal Intensity
Background: Assessment of plaque vulnerability is important in evaluating the future risk of stroke. Plaque characteristics and plaque volume are important components of plaque vulnerability. Expansive remodeling (ER) is one of the criteria for vulnerable plaque in the coronary arteries, and influences the plaque volume. The aim of this study is risk stratification of carotid plaque through the evaluation of quantitative ER and MRI plaque signal intensity.
Methods: We studied and obtained both pre-operation carotid MRI T1-weighted axial and long axis images of 72 patients who underwent carotid endarterectomy or carotid aretery stenting. ER ratio (ERR) was calculated from the ratio of the linear diameter of the artery at the thickest segment of the plaque to the diameter of the artery beyond any poststenotic dilatation on the long axis image on carotid MRI. We also calculated relative plaque signal intensity (rSI) from the axial image and grouped the patients as follows: Group A, rSI≥1.4 and ERR≥1.8; Group B, rSI<1.4 and ERR≥1.8; Group C, rSI≥1.4 and ERR<1.8; Group D, rSI<1.4 and ERR<1.8. Ischemic events within 6 months were retrospectively evaluated in each group.
Results: Of the 72 patientis, the number of patients in each group was as follows: Group A, 20 patients; B, 12 patients; C, 19 patients; D, 21 patients. Fifteen patients (75%) in Group A, 6 patients (50%) in Group B, 8 patients (42%) in Group C and 7 patients (33%) in Group D had ischemic events within 6 months. Ischemic events in Group A was significantly higher than in Group C and D (p<0.05, p<0.001).
Conclusion: The combined assessment of plaque characterization with MRI and morphological evaluation using ERR are useful in risk stratification for carotid lesions.
- © 2012 by American Heart Association, Inc.