Abstract 2541: The Impact of Arterial Remodeling on the Occurrence of Complicated Plaque Features: An in vivo MRI study

Abstract

PURPOSE: Positive Remodeling is considered to be a feature of the vulnerable atherosclerotic plaque. Via magnetic resonance imaging (MRI), we sought to determine the relationship between the prevalence of complex carotid atherosclerotic lesions (AHA-LT6+luminal surface defect, hemorrhage/thrombus or calcified nodule) and arterial remodeling. METHODS&MATERIALS: 175 subjects with 1–99% stenosis as measured by duplex ultrasound had their bilateral carotid arteries imaged at 1.5T. After excluding arteries with previous endarterectomy or poor image quality, there were 260 arteries available for analysis. AHA-LT6, lumen, wall, total vessel (lumen=wall) areas and normalized wall index (NWI = wall area/total vessel area) were determined by the consensus opinion of 2 experienced carotid MRI reviewers. RESULTS: There was a highly significant negative correlation between minimum lumen area and AHA-LT6, and highly significant positive correlations between maximum wall area / maximum NWI and AHA-LT6 (see Table ). No significant correlation between occurrence of complicated plaque features and maximum total vessel area was observed. Furthermore, arteries with AHA-LT6 had significantly smaller minimum lumen areas, larger mean wall areas and larger maximum NWIs than arteries without AHA-LT6 (p<.001). No significant difference between arteries with and without AHA-LT6 was found for the total vessel area. CONCLUSIONS: Occurrence of complicated AHA Type VI lesions is related to arterial lumen and wall dimensions. The absence of a significant correlation between total vessel area and AHA Type VI lesions suggests that outward remodeling has a minor role in the development of these complicated lesions in carotid arteries. Correlation of Quantitative Plaque Area Measurements with the Occurrence of Complicated Plaque Featu