From the Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, K 23 Queen Square, Holborn, London WC1N 3BG, England (A.D.N., H.R.J.); NESMOS (Neurosciences, Mental Health and Sensory Organs) Department, School of Medicine and Psychology, Sapienza University, Rome, Italy (A.D.N.); Division of Surgery and Interventional Science (S.F.C., T.R., H.R.J.), Centre of Medical Imaging (D.A., J.E.M.), Stroke Research Centre, Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology (M.M.B.), and Academic Neuroradiological Unit, Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology (H.R.J.), University College London, London, England; Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, England (J.G.); Department of Vascular Surgery, University of Western Australia, Fiona Stanley Hospital, Perth, Australia (T.R.); and Department of Medical Physics and Biomedical Engineering, University College London Hospitals National Health Service (NHS) Foundation Trust, London, England (M.S.).
Radiology. 2020 Dec;297(3):652-660. doi: 10.1148/radiol.2020200225. Epub 2020 Oct 13.
BackgroundStenosis of the internal carotid artery has a higher risk for stroke. Many investigations have focused on structure and plaque composition as signs of plaque vulnerability, but few studies have analyzed hemodynamic changes in the brain as a risk factor.PurposeTo use 3-T MRI methods including contrast material-enhanced MR angiography, carotid plaque imaging, and arterial spin labeling (ASL) to identify imaging parameters that best help distinguish between asymptomatic and symptomatic participants with carotid stenosis.Materials and MethodsParticipants with carotid stenosis from two ongoing prospective studies who underwent ASL and carotid plaque imaging with use of 3-T MRI in the same setting from 2014 to 2018 were studied. Participants were assessed clinically for recent symptoms (transient ischemic attack or stroke) and divided equally into symptomatic and nonsymptomatic groups. Reviewers were blinded to the symptomatic status and MRI scans were analyzed for the degree of stenosis, plaque surface structure, presence of intraplaque hemorrhage (IPH), circle of Willis collaterals, and the presence and severity of arterial transit artifacts (ATAs) at ASL imaging. MRI findings were correlated with symptomatic status by using tests and the Fisher exact test.ResultsA total of 44 participants (mean age, 71 years ± 10 [standard deviation]; 31 men) were evaluated. ATAs were seen only in participants with greater than 70% stenosis (16 of 28 patients; < .001) and were associated with absence of anterior communicating artery (13 of 16 patients; = .003). There was no association between history of symptoms and degree of stenosis (27 patients with ≥70% stenosis and 17 patients with <70%; = .54), IPH (12 patients with IPH and 32 patients without IPH; = .31), and plaque surface structure (17 patients with irregular or ulcerated plaque and 27 with smooth plaque; = .54). Participants with ATAs ( = 16) were more likely to be symptomatic than were those without ATAs ( = 28) ( = .004). Symptomatic status also was associated with the severity of ATAs ( = .002).ConclusionArterial transit artifacts were the only factor associated with recent ischemic symptoms in participants with carotid stenosis. The degree of stenosis, plaque ulceration, and intraplaque hemorrhage were not associated with symptomatic status.© RSNA, 2020See also the editorial by Zaharchuk in this issue.
背景
颈内动脉狭窄发生中风的风险更高。许多研究集中于结构和斑块组成作为斑块易损性的标志，但很少有研究分析脑血流动力学变化作为危险因素。
目的
使用包括对比增强磁共振血管造影、颈动脉斑块成像和动脉自旋标记（ASL）的 3-T MRI 方法，确定有助于区分无症状和有症状颈动脉狭窄患者的最佳影像学参数。
材料与方法
本研究纳入了 2014 年至 2018 年在同一环境下接受 ASL 和颈动脉斑块成像的两项正在进行的前瞻性研究中的颈动脉狭窄患者，这些患者均为无症状参与者。通过临床评估近期症状（短暂性脑缺血发作或中风），并将参与者平均分为有症状和无症状两组。评估者对症状状态不知情，分析 MRI 扫描以评估狭窄程度、斑块表面结构、斑块内出血（IPH）、Willis 环侧支循环以及 ASL 成像的动脉通过性伪影（ATA）的存在和严重程度。使用 检验和 Fisher 确切检验将 MRI 结果与症状状态相关联。
结果
共评估了 44 名参与者（平均年龄，71 岁±10[标准差]；31 名男性）。ATA 仅见于大于 70%狭窄的参与者（28 名患者中的 16 名；<.001），与前交通动脉缺失相关（16 名患者中的 13 名；=.003）。症状史与狭窄程度之间无相关性（27 名患者狭窄程度大于 70%，17 名患者狭窄程度小于 70%；=.54），与 IPH 之间也无相关性（12 名患者有 IPH，32 名患者无 IPH；=.31），与斑块表面结构之间也无相关性（17 名患者斑块不规则或溃疡，27 名患者斑块光滑；=.54）。有 ATA（=16）的参与者比没有 ATA（=28）的参与者更有可能出现症状（=.004）。症状状态也与 ATA 的严重程度相关（=.002）。
结论
在颈动脉狭窄患者中，动脉通过性伪影是唯一与近期缺血性症状相关的因素。狭窄程度、斑块溃疡和斑块内出血与症状状态无关。
©2020RSNA
