Detecting Intracranial Vessel Wall Lesions With 7T-Magnetic Resonance Imaging: Patients With Posterior Circulation Ischemia Versus Healthy Controls

Background and Purpose - Vessel wall magnetic resonance imaging sequences have been developed to directly visualize the intracranial vessel wall, enabling detection of vessel wall changes, including those that have not yet caused luminal narrowing. In this study, vessel wall lesion burden was assessed in patients with recent posterior circulation ischemia using 7T-magnetic resonance imaging and compared with matched healthy controls. Methods - Fifty subjects (25 patients and 25 matched healthy controls) underwent 7T-magnetic resonance imaging with an intracranial vessel wall sequence before and after contrast administration. Two raters scored the presence and contrast enhancement of arterial wall lesions in individual segments of the circle of Willis and its primary branches. Total burden and distribution of vessel wall lesions and lesion characteristics (configuration, thickening pattern, and contrast enhancement) were compared both between and within both groups. Results - Overall, vessel wall lesion burden and distribution were comparable between patients and controls. Regarding individual arterial segments, only vessel wall lesions in the posterior cerebral artery were more frequently observed in patients (18.0%) than in controls (5.4%; P=0.003). Many of these lesions showed enhancement, both in patients (48.9%) and in controls (43.5%; P=0.41). In patients, the proportion of enhancing lesions was higher in the posterior circulation (53.3%) than in the anterior circulation (20.6%; P=0.008). Conclusions - Although overall intracranial vessel wall lesion burden and contrast enhancement were comparable between patients with recent posterior circulation ischemia and healthy controls, this study also revealed significant differences between the 2 groups, suggesting an association between posterior circulation lesion burden/enhancement and ischemic events.