Plaque Distribution of Stenotic Middle Cerebral Artery and Its Clinical Relevance

Abstract

Background and Purpose-Microanatomy studies reveal that most penetrating branches of middle cerebral artery (MCA) arise from the dorsal-superior surface of the trunk. Using high-resolution MRI, we sought to explore the plaque distribution of MCA atherosclerosis and its clinical relevance in relation to the orifices of penetrating arteries. Methods-We retrospectively analyzed the imaging and clinical data of 86 patients with atherosclerotic MCA stenosis. On high-resolution MRI, plaques were categorized based on the involvement of the superior, inferior, ventral, or dorsal MCA wall. The relationship of plaque distribution and clinical presentation was analyzed. Results-A total of 92 stenotic MCAs (40 symptomatic and 52 asymptomatic) on 828 image slices were studied.Overall, of the 251 slices with identified plaques, plaques were more frequently located at the ventral (44.8%) and inferior (31.7%) wall as compared with the superior (14.3%) and dorsal wall (9.0%; PϽ0.001). Symptomatic MCA stenosis had more superior (Pϭ0.016) and less inferior (Pϭ0.023) wall plaques than asymptomatic stenosis. Within the group of symptomatic MCA stenosis, vessels with penetrating artery infarctions had more superior (Pϭ0.001) but less ventral (Pϭ0.038) and inferior (Pϭ0.024) plaques than without penetrating artery infarctions. Conclusions-MCA plaques tend to locate opposite to the orifices of penetrating arterial branches. Further studies are required to investigate whether MCA plaque distribution is an independent determinant of stroke occurrence and its subtypes. (Stroke. 2011;42:2957-2959.)

Intracranial Vessel Wall MRI: Principles and Expert Consensus Recommendations of the American Society of Neuroradiology

“…53 Similarly, intracranial VW-MR imaging has shown that MCA plaque is more common in the ventral (45%) or inferior (32%) parts of the wall than in the superior (14%) or dorsal (9%) parts where branches arise, 54,55 and basilar artery plaque is more common in the ventral part of the wall, which is opposite the origins of the branches. 56 However, some atherosclerotic plaque does arise close to ostia, and VW-MR imaging has confirmed that indeed MCA plaque with associated infarction has more superior wall involvement than plaque without infarction (24% versus 7%).…”

“…56 However, some atherosclerotic plaque does arise close to ostia, and VW-MR imaging has confirmed that indeed MCA plaque with associated infarction has more superior wall involvement than plaque without infarction (24% versus 7%). 54 Angioplasty can generate a "snow plow" effect, in which atheromatous material is pushed from the treated artery into a branch. In the coronary circulation, location of atherosclerotic plaque close to a branch ostium increases the risk of branch occlusion following angioplasty and stent placement.…”

Imaging the Intracranial Atherosclerotic Vessel Wall Using 7T MRI: Initial Comparison with Histopathology

“…1 In recent years, several MR imaging sequences have been developed on 3T and 7T field strengths that specifically visualize the intracranial arterial vessel wall, enabling direct assessment of intracranial atherosclerotic plaques. [2][3][4][5][6][7][8] Similar to studies of carotid artery atherosclerosis almost a decade ago, several studies have recently attempted to characterize intracranial plaque components, such as intraplaque hemorrhage, 9,10 fibrous cap, 11 and lipid components, by using MR imaging. 12,13 For the carotid arteries, much research has already been done validating image signal heterogeneity within the vessel wall with histology, the criterion standard.…”

Intracranial vessel wall MRI: a review of current indications and future applications

“…e TOF MRA shows minimal stenosis in the right M1 segment (white arrow) of the middle cerebral artery, at the origin of the lenticulostriate perforators that supplied the distribution of the ischemic stroke. f Sagittal reconstruction of the same right M1 segment again demonstrates eccentric wall enhancement, consistent with recently symptomatic atherosclerotic plaque, and outward remodeling at the site of the enhancement irregularly surfaced with increased ratio of plaque thickening to patent vessel lumen [27][28][29][30][31][32]. Among MCA plaques with associated deep penetrating artery infarctions, plaque tended to be more superior and less ventral [28,31].…”

“…f Sagittal reconstruction of the same right M1 segment again demonstrates eccentric wall enhancement, consistent with recently symptomatic atherosclerotic plaque, and outward remodeling at the site of the enhancement irregularly surfaced with increased ratio of plaque thickening to patent vessel lumen [27][28][29][30][31][32]. Among MCA plaques with associated deep penetrating artery infarctions, plaque tended to be more superior and less ventral [28,31]. Symptomatic MCA plaques typically have positive remodeling, characterized by outward remodeling of the stenotic vessel area [26,28,29,33], an association first demonstrated in coronary arterial atherosclerosis [34,35].…”