磁共振斑块成像技术临床应用的现在与未来

磁共振斑块成像技术已被广泛应用于颈动脉粥样硬化斑块特征的研究中。经组织学验
证,这些技术能够准确评价斑块负荷、组织成分、纤维帽完整性和炎症反应。本综述将从以下几个
方面阐述磁共振斑块成像技术在临床实践中的潜在应用价值：①在易损斑块表面破裂前,磁共振斑
块成像能够对其进行早期识别,从而预防缺血性卒中;②颈动脉斑块磁共振特征可能有助于制订临
床治疗策略;③磁共振斑块成像是监测颈动脉粥样硬化病变他汀类药物治疗效果的有效手段。     

颈动脉粥样硬化疾病的高分辨磁共振成像研究进展

颈动脉粥样硬化疾病及并发血栓形成是脑血管疾病的主要原因之一。高分辨磁共振成像
（high-resolution magnetic resonance imaging,HRMRI）是一项理想的、非侵入性的进行颈动脉粥样硬化
斑块的检查方式,可以从斑块负荷、斑块成分、血流动力学等方面更好地评价动脉粥样硬化病变,并
且因其对斑块转归检测的有效性及敏感性,成为临床新药物疗效的评价方式。     

基于磁共振成像的颈动脉粥样硬化相 关血流动力学研究进展

动脉粥样硬化斑块常发生于血流动力学状态复杂的区域，显示局部血流的流体力学特性
在动脉粥样硬化病变发生发展中起到重要作用。基于磁共振成像结合图像后处理技术，可对动脉血
流动力学状态进行评估。既往研究已经对正常和狭窄颈动脉的血流动力学特征进行了分析；而血流
动力学因素与斑块易损性之间的相关性也已经得到证实。包括管壁应力、压力等动脉血流动力学参
数的综合作用是斑块发生发展变化中的重要因素。     

磁共振斑块成像与缺血性卒中的相关性研究进展

动脉粥样硬化易损斑块破裂是导致缺血性卒中的主要原因。与组织病理学对照研究证实,
高分辨率磁共振成像可以无创性评价动脉粥样硬化斑块的负荷、成分及其易损性。大量研究显示,
脑血管粥样硬化斑块的磁共振表现特征与缺血性卒中具有明显的相关性。本文将从磁共振斑块成
分特征与缺血性脑血管事件的相关性方面进行综述,为缺血性卒中的病因学诊断和疾病的预防提供
重要依据。     

高分辨MRI技术对动脉粥样硬化斑块的 评价

识别动脉粥样硬化斑块及其易损性能有效地预测高危人群,减低心脑血管临床事件的发
生。磁共振作为一项无创检查手段,可以观察斑块的形态和易损性,并进行综合评价。本文就磁共
振成像技术对动脉粥样硬化斑块的形态功能学检查做一简要综述。     

卒中高危人群糖化血红蛋白与颈动脉粥样硬化斑块的关系研究

目的 分析卒中高危人群糖化血红蛋白与颈动脉粥样硬化斑块的关系。
方法 2018年5-6月由孝感市中心医院按整群随机抽样方法，随机抽取孝感市城乡各1个社区居民
进行筛查，通过问卷调查、体格检查、实验室检查、颈部血管超声检查筛选卒中高危人群纳入研究。
根据颈动脉超声检测结果将卒中高危人群分为非斑块组和斑块组（颈动脉）。分别采用单因素和多
因素Logistic回归，分析糖化血红蛋白与颈动脉斑块的关系，并根据年龄（60岁）、BM（I 24 kg/m2）、是
否有高血压对研究人群进行分层分析，研究不同特征的卒中高危人群中糖化血红蛋白与颈动脉斑块
的关系。
结果 最终纳入卒中高危人群629例，男性338例（53.74%），平均54.85±8.97岁，糖化血红蛋白平
均浓度为4.70%±1.02%。其中斑块组患者215例（34.18%），非斑块组患者414例（65.82%）。与非斑
块组患者相比，斑块组患者男性、卒中、TIA、高血压、超重患者比例更高，年龄更大，BMI、血压、空
腹血糖、糖化血红蛋白、TC水平更高（均P＜0.01）。校正其他危险因素后，糖化血红蛋白是颈动脉
粥样硬化斑块发生的独立影响因素（每升高1%，OR 1.16，95%CI 1.01～1.31，P =0.018）。分层分析显
示，年龄≥60岁（OR 1.48，95%CI 1.09～2.01，P =0.016）、BMI≥24 kg/m2（OR 1.97，95%CI 1.07～3.64，
P =0.030）、高血压人群（OR 1.31，95%CI 1.06～1.62，P =0.013）中糖化血红蛋白均是颈动脉斑块发生
的独立危险因素。
结论 卒中高危人群糖化血红蛋白与颈动脉斑块的发生密切相关，特别是在年龄≥6 0岁、
BMI≥24 kg/m2和高血压人群中。     

脑侧支循环影像学评价研究进展

本综述阐述了脑侧支循环的特点、侧支循环影像学评价方法及其优点和局限性。主要包
括经颅多普勒超声、磁共振血管成像、计算机断层扫描血管成像、计算机断层扫描灌注成像、数字减
影血管造影、多时相计算机断层扫描血管成像。帮助临床医师在疾病早期选择合适的影像学方法评
价侧支循环状态,指导临床决策和预后。     

颈动脉血管重建术对颈动脉狭窄患者认知功能的影响

颈动脉狭窄会导致患者远期认知功能下降，而既往研究表明颈动脉内膜剥脱术和支架
置入术作为治疗颈动脉狭窄的主要术式，可以改善患者的认知功能，尤其是执行能力等特定领域的
认知水平。进一步研究发现颈动脉血管重建术中栓子的形成，术后脑血流灌注提高，以及神经代谢
水平等改变可能在机制上解释颈动脉重建术后认知功能的变化；此外，围术期炎症反应，血脂水平，
以及基因易感性等都是术后远期认知功能结局的临床预测因素，以上因素对于提高颈动脉狭窄患者
的生活质量、治疗术式的优化具有重要临床意义。     

颈动脉颅外段不稳定斑块与进展性脑梗死的相关性

目的应用高分辨率磁共振成像技术,探讨颈动脉颅外段不稳定斑块与进展性脑梗死的相关性。方法选取颈动脉超声下斑块厚度2mm的患者80例,根据病情38例纳入进展组,42例纳入稳定组,分析2组斑块成分(斑块内出血、偏心脂质坏死核、纤维帽较薄/破裂)及管腔狭窄程度与进展性脑梗死的相关性。结果进展组患者的收缩压、空腹血糖、低密度脂蛋白和超敏C反应蛋白均明显高于对照组(P0.05);三维时间飞跃法磁共振血管造影检查显示颈动脉颅外段轻中度血管狭窄中,进展组与对照组比较,差异无统计学意义(P0.05);进展组中颈动脉颅外段重度血管狭窄和斑块的纤维帽较薄/破裂发生率高,与对照组比较,差异有统计学意义(P0.05)。结论颈动脉颅外段斑块纤维帽较薄/破裂与进展性脑梗死具有显著相关性,可作为脑梗死进展与否的影像学指标。     

儿童脑静脉窦血栓12例临床特征分析

【摘要】
目的 探讨儿童脑静脉窦血栓形成（cerebral venous sinus thrombosis,CVST）发病的危险因素、病因、临床表现、影像学表现及诊治方法。
方法 对2003年1月至2011年6月在北京天坛医院儿科及神经内科就诊的12例儿童脑静脉窦血栓进行回顾性分析。
结果 所有患儿均表现出颅高压症状。鼻窦炎（7例,58.3%）可能为儿童CVST主要发病病因。颅脑磁共振成像（magnetic resonance imaging,MRI）和磁共振静脉成像（magnetic resonance venography,MRV）显示最常见的受累静脉窦为乙状窦和横窦（各11例,占97.1%）。经降颅压、抗凝及对症支持治疗,8例痊愈,4例遗留神经功能缺损。
结论 CVST患儿常以颅高压症状就诊,感染为儿童CVST的最主要危险因素,神经影像学检查能为确诊提供依据,及时治疗可改善预后。     

Carotid atherosclerotic wall imaging by MRI

High spatial resolution magnetic resonance imaging (MRI) is one of the most promising modalities for visualizing the carotid atherosclerotic plaque. MR allows direct visualization of the diseased vessel wall, is capable of characterizing plaque morphology, and can potentially monitor progression of the disease. Though ultrasound and angiography have been the principal methods for determining the severity of carotid atherosclerosis and the need for endarterectomy, these methods only measure percentage of vessel stenosis. There is strong evidence that this is not the best indicator for assessing clinical risk. Improved imaging techniques are therefore needed to reliably identify the high-risk plaques that lead to cerebrovascular events. This article focuses on the current state-of-the-art in MR carotid atherosclerotic plaque imaging to evaluate plaque morphology and composition.     

颈动脉粥样硬化斑块与脑梗死关系的高分辨磁共振研究

目的探讨高分辨磁共振(MRI)对颈动脉粥样硬化斑块与脑梗死关系的评估价值。方法选取驻马店市精神病医院2014-01—2016-01收治的32例经高分辨MRI检查证实的脑梗死患者为试验组,以同期我院体检的行MRI扫描的25例无脑梗死患者作对照(对照组),采用三维时间飞跃法(3D-TOF)、T1加权(T1WI)、T2加权(T2WI)及增强颈部血管成像等扫描序列,分析颈动脉斑块的成分、分型及其与脑梗死的关系。结果试验组有颈动脉粥样硬化斑块者30例(93.75%),无颈动脉粥样硬化斑块者2例(6.25%);对照组有颈动脉粥样硬化斑块者6例(24.00%),无颈动脉粥样硬化斑块者19例(76.00%);试验组颈动脉粥样硬化斑块的发生率明显高于对照组(P0.01)。试验组共发现60块颈动脉粥样硬化斑块,其中Ⅰ~Ⅱ型7块(11.67%),Ⅲ型8块(13.33%),Ⅳ~Ⅴ型19块(31.67%),Ⅵ型21块(35.00%),Ⅶ型2块(3.33%),Ⅷ型3块(5.00%);对照组共发现14块颈动脉粥样硬化斑块,以稳定性斑块为主,Ⅰ~Ⅱ型13块(92.86%),Ⅳ型1块(7.14%)。2组颈动脉不稳定斑块发生率比较差异有统计学意义(P0.05)。脑梗死患者颈总动脉、分叉处及颈内动脉3个部位的粥样硬化斑块分布情况差异无统计学意义(P0.05)。结论高分辨MRI可清晰显示颈动脉粥样斑块的内部成分,且颈动脉粥样硬化斑块与脑梗死的发生有密切的相关性,高分辨MRI可对脑梗死的发生风险作出预测,为临床防治脑梗死及疗效评价提供重要的影像学依据。     

骨髓增殖性肿瘤伴发卒中的临床分析

目的 提高对骨髓增殖性肿瘤伴发卒中诊断和治疗的认识。 方法 收集2008年11月～2011年12月北京天坛医院血液科收治的骨髓增殖性肿瘤伴卒中患者的临床资料、实验室及影像学检查结果［包括病史、年龄、临床表现、颈部血管彩色多普勒超声、颅脑计算机断层扫描（computed tomography,CT）或磁共振成像（magnetic resonance imaging,MRI）、全血细胞计数、JAK2V617F基因突变检查］,并对治疗随访评价。 结果 骨髓增殖性肿瘤伴卒中16例,其中脑梗死13例,脑出血1例,短暂性脑缺血发作2例;脑梗死患者中4例患者梗死复发。真性红细胞增多症7例,原发性血小板增多症4例,原发性骨髓纤维化5例。7例患者卒中于骨髓增殖性肿瘤诊断前发生,8例同时诊断,1例骨髓增殖性肿瘤诊断后发生。13例有不同程度血细胞升高,13例行JAK2基因突变检测,阳性率76.9%。14例行颈部血管彩色多普勒超声检查均显示颈动脉和锁骨下动脉不同程度增厚、斑块形成伴狭窄。16例患者均服用阿司匹林治疗,其中15例患者同时接受羟基脲和（或）α干扰素治疗。 结论 本组病例结果提示,卒中患者需仔细阅读全血细胞计数,重视骨髓增殖性肿瘤的诊断,JAK2基因突变检测有助于骨髓增殖性肿瘤的早期诊断。骨髓增殖性肿瘤患者常伴有颈部血管的结构异常。卒中患者需重视骨髓增殖性肿瘤的诊治。     

Intraplaque Microvascular Flow Signal in Superb Microvascular Imaging and Magnetic Resonance Imaging Carotid Plaque Imaging in Patients with Atheromatous Carotid Artery Stenosis

Carotid artery atherosclerosis is one of the major risk factors for ischemic stroke. Intraplaque neovascularization (IPN) is one of the steps toward the development of vulnerable plaque. Superb microvascular imaging (SMI) is a new ultrasonographic technique for visualizing low-velocity and microvascular flow by clutter suppression to extract flow signals from large to small vessels and enables visualization of intraplaque microvascular flow (IMVF) without echo contrast media. We aimed to investigate the association between IMVF signal in SMI and MRI plaque imaging among patients with atherosclerotic carotid stenosis.We prospectively enrolled patients (>18 years old) with mild to severe carotid stenosis (more than 50% in cross-sectional area) diagnosed by carotid ultrasonography between August 2017 and April 2018, irrespective of sex and history of stroke.A total of 40 patients (31 men, 9 women; mean age, 75.1 ± 10.0 years) were enrolled. SMI revealed IPN findings in 21 patients. SMI clearly visualized the direction of pulsatile flow movement in microvessels and IPN was easily classified into the two types of Type V (n=2) and Type E (n=19). Multivariate logistic regression analysis presented that microvascular flow signal in carotid plaque on SMI was identified as a significant predictor of intraplaque hemorrhage as evaluated by MRI (OR, 8.46; 95%CI, 1.44?49.9; p=0.018).This study demonstrated a significant association between the presence of IMVF signal in SMI and intraplaque hemorrhage characterized by high-intensity lesions on MRI T1-FFE images     

Reproducibility of histological assessment of carotid plaque: implications for studies of carotid imaging

BACKGROUND: Thromboembolism from carotid plaque is an important cause of stroke. Identification of unstable plaque would therefore be clinically useful. Unfortunately, studies of carotid plaque imaging have shown poor agreement with histology. However, this may be due to inconsistent methods and the variability of assessments of carotid plaque histology, rather than inadequate imaging. METHODS: We assessed the reproducibility of histological assessment in 60 plaques, and section-to-section variability along the length of 26 plaques. RESULTS: Kappa values ranged from 0.35 to 0.89 and from 0.44 to 0.68, respectively, for intra- and inter-observer reproducibility. There was considerable section-to-section variability within plaques. CONCLUSIONS: The accuracy of imaging of carotid plaque morphology will be underestimated unless variability in the histology assessment is taken into account.     

Risk factors for periprocedural complications in carotid artery stenting without filter protection

Introduction In highgrade stenosis, carotid artery stenting (CAS) may be chosen as an alternative to carotid surgery. Ischemic periprocedural complications may be documented best with diffusion–weighted MRI (DWMRI). In this prospective study serial DW–MRI and color–coded duplex sonography (CCDS) were used to identify carotid stenosis, which is associated with an increased risk of ischemic events due to CAS. Methods High resolution DW–MRI were performed in 74 out of 77 patients before and after CAS. All MRI scans were analyzed in a blinded manner. With CCDS each carotid stenosis was evaluated according to the grade, length, echo properties and plaque surface. Results In 42 out of 74 patients (56.8 %) a total of 188 new procedure– related DWI–lesions could be detected, while in 32 patients MRI–controls remained normal. Of the lesions 79.25 % had a size < 1 cm. In one major and two minor strokes due to CAS (total complication rate 3.9 %) corresponding territorial infarcts could be demonstrated. A highly significant correlation was found between the length of the stenosis and the incidence of new DWI–lesions (p = 0.0141). In contrast, neither the grade of ICA stenosis nor the sonographic plaque morphology or plaque surface correlated with the number of DWI–lesion in postinterventional scans. Conclusions The length—and not the degree—of an ICA stenosis seems to be the most decisive sonographic factor for estimating the periprocedural risk of embolism. DWI–lesions are much more frequent than clinical complications and may represent an important surrogate marker for improving the techniques of carotid artery stenting, especially comparing the benefit of different mechanical protection devices.     

Multifocal arterial wall contrast – enhancement in ischemic stroke: A mirror of systemic inflammatory response in acute stroke

PurposeIntracranial plaque gadolinium enhancement revealed by high-resolution MRI imaging (HR MRI) is considered as a marker of plaque inflammation, a contributing factor of plaque unstability. The aim of the present study was to assess the distribution of gadolinium enhancement in intracranial atherosclerosis.MethodsSingle center analysis of ischemic stroke patients with intracranial atherosclerotic stenosis of M1 or M2 segments of middle cerebral artery, or terminal internal carotid artery (ICA) based on CT-angio or MR-angio. High-resolution MRI imaging (HRMRI) was performed within 6 first weeks following the index event, with 3DT2 BB (black-blood) and 3D T1 BB MR sequences pre and post-contrast administration.ResultsWe identified 8 patients with 14 plaques, 4 were deemed non-culprit and 10 culprit. All culprit plaques (10/10 plaques) and 3 out of 4 non-culprit plaques showed a gadolinium enhancement.ConclusionAt the acute/subacute stage of stroke, a gadolinium enhancement may affect multiple asymptomatic intracranial plaques and may reflect a global inflammatory state.     

Immunohistochemical analysis of MMP-9 and COX-2 expression in carotid atherosclerotic plaques among patients undergoing carotid endarterectomy: A prospective study

BackgroundMatrix metalloproteinase-9 protein (MMP-9) and cyclooxygenase-2 (COX-2) proteins may have a role in remodelling of atherosclerotic plaques. We analysed and compared the radiological, histological and immunohistochemical characteristics of carotid atherosclerotic plaques between symptomatic and asymptomatic patients who underwent carotid endarterectomy (CEA).MethodsThis prospective single-blinded study included 31 patients (70 [64-75] years, 58% males, 42% symptomatic) who underwent CEA and a total of 155 carotid plaque sections that were analysed. Preoperative assessment and multimodality diagnostic imaging with magnetic resonance imaging (MRI) or computed tomography angiography (CTA), histological and immunohistochemical analyses of carotid plaques including the expression of MMP-9 and COX-2 proteins were performed.ResultsSymptomatic and asymptomatic patients did not significantly differ in respect to preoperative characteristics. Unstable plaques were detected in 12/13 (92.3%, p = 0.020) symptomatic patients using MRI or CTA. There was no perioperative mortality and perioperative outcomes were comparable in both groups. A significantly higher expression of MMP-9 in macrophages was observed among symptomatic patients (p = 0.020). ROC curve analysis showed statistically significant associations of both the higher intensity of COX-2 staining in CD68 PG-M1 positive macrophages (area under the curve [AUC]=0.701, p = 0.014) and higher MVD (AUC=0.821, p < 0.001) within the plaque with cerebrovascular symptoms. The expression of COX-2 and the intensity of COX-2 staining in macrophages within the unstable carotid plaques detected by preoperative MRI or CTA were significantly higher (76.1% vs. 40.0%, p = 0.038; 76.2% vs. 30.0%, p = 0.01, respectively).ConclusionsAdvanced non-invasive multimodality diagnostic imaging including MRI or CTA is reliable in differentiating unstable from stable carotid plaques. High expression of MMP-9 and COX-2 in macrophages within the symptomatic plaque is associated with increased risk of cerebrovascular complications.Trial RegistrationThis study has been registered at the ISRCTN registry (ID ISRCTN46536832), isrctn.org Identifier: https://www.isrctn.com/ISRCTN46536832