Abstract 14039: High Intensity Signals on TOF-MRA of Atherosclerotic Carotid Plaque Indicate a High Risk for Cerebral Embolism After Carotid Artery Stenting
Background: A major disadvantage of carotid artery stenting (CAS) compared to carotid endarterectomy (CEA) is the increased risk of cerebral embolism. A simple screening method to detect plaques that may produce emboli while stenting is needed. This study examined whether high-intensity signals (HIS) on maximum intensity projection (MIP) images from routine time-of-flight (TOF) magnetic resonance angiography (MRA) could provide useful information.
Methods: [Validation study] TOF-MRA images from thirty CEA patients were compared to the excised surgical specimens. [Clinical study] Post-operative ipsilateral ischemic brain lesions were detected on post-procedural diffusion-weighted imaging by MRI (DWI-MRI) from 112 patients treated by CAS.
Results: [Validation study] A total of 131 histological sections from thirty CEA surgical specimens were immunohistochemically evaluated. The percent area of intraplaque hemorrhage (IPH) stained by glycophorin A was significantly larger in HIS-positive (HIS-P) plaques (51.8±9.8%) than in HIS-negative (HIS-N) plaques (8.6±9.4%, P<0.001). Macrophages, as stained by CD-68, were more common in HIS-P plaques (662±274 cells/5 fields) than in HIS-N plaques (232±71 cells/5 fields P<0.001). [Clinical study] Brain ischemic lesions on post-procedural DWI-MRI were more frequent in HIS-P plaques (25/38, 65.8%) than in HIS-N plaques (26/74, 35.1%; P=0.006) (Sensitivity: 65%, Specificity: 64%). Multivariate logistic regression analysis identified HIS on MIP images from TOF-MRA was an independent predictor of post-operative ipsilateral ischemic brain lesions (odds ratio: 3.34; 95% confidence interval: 1.43-7.86).
Conclusion: The results from this study strongly suggest an association between the presence of carotid IPH as detected by MIP images from TOF-MRA and brain ischemic lesions on post-procedural DWI-MRI. This valuable finding can assist the pre-operative choice between CAS and CEA.
- © 2011 by American Heart Association, Inc.