Abstract TP121: High-Resolution Magnetic Resonance Imaging Characteristics of Intracranial Atherosclerotic Plaque and Perforating Artery

Abstract

Objective: Intracranial atherosclerotic disease (ICAD) is a cause of ischemic stroke, with the middle cerebral artery (MCA) being commonly affected. The vulnerable plaque is considered as the cause of stroke. High resolution magnetic resonance imaging (HR-MRI) can help us assess the morphology characteristics and vulnerability of intracranial atherosclerosis plaque. HR-MRI could also provide us such information as microvascular structure of perforating arteries from MCA. The aim of our study was to distinguish the differences in the plaque morphology between symptomatic and asymptomatic MCA stenoses, and the relationship between MCA stenosis and perforating artery. Method: 41 MCAs with symptomatic stenoses and 33 MCAs with asymptomatic stenoses (both between 50% and 99%) were included. The characteristics of plaques and the perforating arteries were evaluated by HR-MRI. Results: Between symptomatic and asymptomatic MCA stenosis groups,vessel morphological characteristics such as the degree of stenosis, remodeling index, wall area index didn’t differ. However, patients with symptomatic MCA stenoses had heavier plaque burden (79.74 ± 1.380 vs 66.72 ± 2.776, P < 0.001). , Symptomatic MCA stenoses showed stronger plaque gadolinium enhancement, including bigger ROI area (4.27 ± 0.266 vs 2.75 ± 0.197 P < 0.001), higher enhancement index (0.46 ± 0.061 vs 0.20 ± 0.067 P = 0.005) and larger enhancement volume (116.34 ± 21.960 vs 35.21 ± 6.535 P < 0.001). With multivariate regression analysis, the plaque burden, the region of interested area, and the enhancement index were independently associated with symptomatic MCA stenosis. The number of perforating arteries of MCAs with moderate to severe stenoses was less than that of normal controls (symptomatic MCA: 3.82 ± 0.165, asymptomatic MCA: 3.85 ± 0.177, normal MCA :4.47±0.162, P=0.006). Conclusions: The plaque burden may be a new index in assessing the vulnerability of intracranial atherosclerosis plaques. The plaque burden, the region of interested area, and the enhancement index are independently associated with symptomatic MCA stenosis. The perforating arteries from symptomatic and asymptomatic MCA stenosis are both less than those from normal MCA controls.