颅内动脉高分辨磁共振成像研究进展

颅内动脉粥样硬化是缺血性脑卒中最常见原因,症状性颅内动脉粥样硬化不仅与管腔狭窄程度有关,还与斑块的特点有关.动脉高分辨磁共振成像是目前唯一可以实现活体内动脉管壁结构分析的无创技术,初步研究已显示动脉高分辨磁共振成像具有显示颅内动脉粥样硬化斑块的潜力.就颅内动脉高分辨磁共振成像的硬件要求、扫描序列及临床应用进行综述.     

高分辨率MRI在颅内动脉斑块的应用研究

目的 探讨高分辨率磁共振成像(HR-MRI)在颅内动脉斑块的临床应用价值,比较多种MR扫描技术对有临床症状脑卒中患者的动脉斑块及其供血区域脑卒中的辨别分析.方法 回顾性分析21例有缺血性脑卒中症状的颅内动脉粥样硬化患者的影像资料及临床指标,所有患者均行HR-MRI、磁共振血管成像(MRA)、扩散加权成像(DWI)及常规...     

3.0 T HRMRI对脑动脉粥样硬化显像优势的初步研究

目的 应用3.0T高分辨率磁共振成像(high-resolution MRI,HRMRI)研究MRA未见明确狭窄的急性有症状腔隙性脑梗死患者脑动脉粥样硬化情况.方法 搜集2013年9月至2014年4月在南方医院住院的47例患者,所有患者均为MRI常规扫描发现急性腔隙性梗死灶、3D-TOF法MRA未见明确狭窄后,进一步行HRMRI检查.31例HRMRI提示中度以上狭窄后进一步行DSA检查.结果 大脑中动脉责任斑块位置以上壁和下壁多见,基底动脉以前壁和后壁居多,28例责任斑块突入或覆盖穿支动脉开口;HRMRI最狭窄处狭窄率与DSA狭窄程度有显著相关性(P＜0.001),HRMRI显示的血管重构与DSA狭窄程度之间有相关性(P＜0.05),MRA局部管腔信号是否减低与DSA血管狭窄有相关性(P＜0.05).结论 3.0 T HRMRI在评价脑动脉管壁结构有明显的优势,与3D-TOF MRA互补,可以较好地评价脑动脉粥样硬化情况,指导临床早期进行正确的干预和治疗.     

颅内动脉易损性粥样硬化斑块MRI研究进展

脑卒中是严重威胁人类健康特别是中老年人健康的常见病,具有发病率、致残率、病死率高的特点,给社会和家庭带来沉重负担.据报道,亚洲人群中40％以上的缺血性卒中是由颅内动脉病变引起[1].其中颅内动脉粥样硬化斑块所导致的管腔狭窄和易损斑块破裂、血栓形成导致管腔闭塞引起的缺血性卒中是最常见的病因.通过影像学方法研究颅内动脉易损斑块破裂机制、早期检测易损斑块,可对缺血性脑卒中患者进行风险评估,有效指导临床治疗[2].因此,笔者对近年来文献报道的颅内动脉易损性粥样硬化斑块的多模态MRI研究进行综述.     

颈动脉血管超声对脑梗死临床诊断价值

现已证实,大多数缺血性脑血管病的发作与动脉粥样硬化有关,是由于颈动脉分叉处的动脉粥样硬化斑块栓子脱落或颅内动脉栓塞或颈内动脉狭窄、闭塞所致的低灌注引起。本研究对72例脑梗死患者颈动脉颅外段进行了超声多普勒检测,旨在探讨脑梗死患者颈动脉硬化斑块数量、部位、狭窄程度,为临床诊断及治疗提供依据。     

三维T1加权可变反转角快速自旋回波序列管壁成像技术在颅内动脉狭窄支架术后随访中的应用

【摘要】 目的 探讨三维T1加权可变反转角快速自旋回波序列（3D T1- SPACE）血管壁成像技术在颅内动脉狭窄支架植入术后随访中的应用价值。方法 前瞻性纳入2017年4月至2018年6月河南省人民医院收治的15例颅内动脉粥样硬化性重度狭窄支架植入术后6～8个月患者,分别接受3D T1- SPACE扫描和DSA造影检查,评价术后支架内管腔狭窄程度和血管壁强化情况。采用Pearson相关分析比较支架植入术后两种血管成像技术测量狭窄率的一致性。 结果 15例患者中植入Enterprise支架8例,Wingspan支架7例;术前平均狭窄率为（81.60±8.67）%,随访复查DSA狭窄率为40（30～72）%;DSA复查支架内再狭窄（ISR）发生率为26.7%（4/15）。3D T1- SPACE测得术后狭窄率为35（30～75）%,增强扫描显示5例支架内斑块强化,其中强化程度2级4例（均为ISR患者）,1级1例。Pearson相关分析显示r=0.959,P＜0.05,Bland Altman图显示全部数据点均位于一致性界限内（ｘ±1.96s）。结论 3D T1- SPACE作为一种无创性血管成像技术,表现出与DSA良好的一致性,可应用于颅内动脉狭窄支架植入术后随访。     

三维DSA 技术在脑血管病诊断与血管内治疗中的应用

目的评价三维DSA（3D DSA）技术在脑血管病诊断及治疗中的应用价值。方法对60例患者所做3D DSA影像与传统二维DSA（2D DSA）进行比较，分析颅内动脉瘤及动脉狭窄在3D DSA上的影像表现。结果与2D DSA相比，3D DSA在对动脉瘤显示有优越性；但对脑动脉狭窄的显示无明显差异。结论3D DSA可以充分显示动脉瘤的形态、位置以及周围解剖关系，并可以从剖面观察病变血管内情况，对斑块稳定性的判断有一定优势，在介入治疗过程中具有重要价值。     

基于高分辨力MR血管壁成像对症状性颅内血管狭窄的脑卒中病人预后的影响因素分析

目的基于高分辨MR血管壁成像技术探究症状性颅内血管狭窄的脑卒中病人预后的危险因素。方法本研究回顾性分析2016年1月—2017年3月就诊于我院神经内科的34例症状性颅内血管狭窄的脑卒中病人资料,利用高分辨MR血管壁成像技术,分析病人颅内斑块的影像特点,并于出院3个月后对病人进行改良Rankin量表(m RS)评分,据此将病人分为预后好组与预后差组。采用t检验或Fisher确切概率检验对2组病人的临床资料及斑块稳定性、斑块成分进行比较,通过Logistic回归分析脑卒中病人预后差的独立危险因素。结果 2组病人的糖尿病病史、高血压病史、管腔狭窄率50%及斑块的稳定性差异均有统计学意义(均P0.05)。预后差组中不稳定性斑块占比(78%)高于稳定性斑块的(22%),预后好组中不稳定性斑块占比(36%)低于稳定性斑块的(64%),2组斑块稳定性差异有统计学意义(P=0.031)。预后差组中斑块内出血和脂质坏死核心所占比例高于预后好组,2组间差异均有统计学意义(均P0.05);预后差组与预后好组斑块内钙化及管腔狭窄率50%所占比例差异均无统计学意义(均P0.05)。高血压病病史、糖尿病病史、颅内动脉狭窄度、斑块的稳定性是脑卒中预后差的独立危险因素。结论高分辨MR血管壁成像技术对症状性颅内血管狭窄的脑卒中病人预后具有很好的评估价值。影响预后的独立因素包括高血压病病史、糖尿病病史、颅内动脉狭窄程度及斑块的稳定性,其中斑块是否稳定及颅内动脉狭窄程度是最关键的两个因素。     

颅内支架植入治疗脑血管狭窄32例护理体会

脑卒中是引起人类致残、致死的第三大常见疾病,颅内脑动脉中重度狭窄是急性脑梗死的主要原因。60%的脑梗死患者存在程度不等的颅内外动脉狭窄和粥样硬化斑块形成。血管内介入治疗凭借其创伤小、并发症少、疗效显著等优点逐渐成为治疗脑血管狭窄的重要手段。我科自2012-10~2013-08共治疗颅内血管支架植入患者32例,现总结如下。     

缺血性卒中病人颅内动脉硬化斑块的HRMRI特征及相关临床危险因素研究

目的利用3.0 T高分辨力MR成像(HRMRI)技术分析缺血性卒中病人颅内责任动脉斑块特征,并探讨颅内动脉不稳定斑块的临床相关危险因素。方法共纳入49例缺血性脑卒中病人行颅内动脉HRMRI检查,男35例,女14例,年龄31~81岁,平均年龄(60.73±12.4)岁。根据病人斑块与缺血区责任动脉的关系分为责任动脉斑块组和非责任动脉斑块组,分析2组病人的HRMRI特征。根据斑块的强化程度分为明显强化组和非明显强化组,分析斑块强化程度与临床相关危险因素的关系。计数资料采用χ2检验,计量资料采用t检验进行统计学分析。结果 49例病人共196处斑块,其中责任动脉斑块70处(35.7%),非责任动脉斑块126处(64.3%);2组间的管腔狭窄程度、斑块明显强化的比例等差异有统计学意义(P0.001),责任动脉斑块所致的管腔狭窄程度更为严重、明显强化的比例更高(P0.001)。明显强化组与非明显强化组之间的年龄、性别、高血压、糖尿病、吸烟史、既往卒中史及家族史差异均无统计学意义。非明显强化组的低密度脂蛋白/高密度脂蛋白(LDL/HDL)比值低于明显强化组(分别为1.95±0.62和2.53±0.94,P=0.048)。结论颅内动脉粥样硬化斑块的强化与缺血性卒中事件的发生密切相关。斑块的强化程度能够反映斑块的稳定性。颅内动脉粥样硬化常见的危险因素并不能完全反映斑块的稳定性,LDL/HDL比值升高有可能作为不稳定斑块的预测因子。     

3.0T高分辨率磁共振在基底动脉粥样斑块特征分析中的初步探讨

目的 探讨3.0T高分辨率磁共振在基底动脉(BA)粥样硬化的重构模式及斑块的分布特征.方法 对90例经数字减影血管造影(DSA)确诊的动脉粥样硬化性BA中重度狭窄(50％～99％)患者进行分析.测定BA患者最狭窄层面的管腔面积、血管面积、参考管腔面积和参考血管面积;统计斑块在最狭窄层面的分布位置.比较阴性重构组及阳性重构组之间的定量及定性结果有无统计学差异,并统计最狭窄层面斑块的分布位置.结果 本研究最终纳入51例患者,其中阳性重构患者占72.5％(37/51),阴性重构患者占27.5％(14/51).相对于阴性重构组,阳性重构组具有较大的斑块面积斑块负重百分比以及较大的最大管壁厚度.在本研究中,BA斑块主要分布于腹侧壁.结论 3.0T高分辨率磁共振对于BA狭窄重构模式及斑块分布特征的评估具有一定价值.     

高分辨血管壁MRI在颅内动脉疾病中的诊断价值

目的 探讨高分辨血管壁磁共振成像(high resolution vessel wall magnetic resonance imaging,HRVW-MRI)在颅内动脉多种疾病中的诊断价值.方法 选取颅内动脉壁高分辨磁共振检查的135例患者,经临床对症治疗及与DSA和临床诊断结果对照.结果 由影像科2名主治医师初步...     

High resolution MR imaging in patients with symptomatic middle cerebral artery stenosis

Purpose

High resolution magnetic resonance imaging (HRMRI) has been used as an imaging modality to depict the intracranial artery wall. The aim of this study was to compare images of the vessel wall between symptomatic and asymptomatic atherosclerotic plaques of the middle cerebral artery (MCA) using HRMRI.

Materials and methods

From September 2009 to August 2010 we prospectively screened consecutive patients for MCA stenosis using time-of-flight (TOF) MR angiography. We studied 14 patients with symptomatic MCA stenosis and 16 patients with asymptomatic MCA stenosis. The HRMRI protocol included three different scans: T1-, T2-, and proton density (PD)-weighted black blood MRI. The cross-sectional images of the MCA wall on HRMRI were compared between the two groups based on the degree of stenosis, remodeling ratio, outward or inward remodeling, plaque signal intensity, plaque surface irregularity, and presence of an intact inner wall.

Results

The degree of MCA stenosis and the ratio of plaque thickening to patent lumen in the symptomatic group were significantly higher than in the asymptomatic group. Outward remodeling of the stenotic area in symptomatic group was significantly higher than that seen in the asymptomatic group, and the reverse was true for inward remodeling of the stenotic area (it was significantly higher in the asymptomatic group compared to the symptomatic group). T2- and PD-weighted high signal foci, eccentric wall thickening, and plaque volume in the stenotic area were all similar between the two groups.

Conclusions

HRMRI has the potential to distinguish between atherosclerotic plaques in symptomatic and asymptomatic MCA stenoses.     

深穿支动脉和浅表穿支动脉供血区梗死病人颅内动脉管壁特征的高分辨力MRI研究

目的应用全脑高分辨MRI(HRMRI)技术比较分析大脑中动脉浅表穿支动脉区梗死(SPI)和深穿支动脉区梗死(DPI)病人的颅内动脉管壁特征,以阐述其潜在的发病机制。方法回顾性分析41例[男31例,女10例;平均年龄(51.9±11.33)岁]急性期SPI和DPI行全脑HRMRI检查的病人,HRMRI采用优化的3D可变翻转角度快速自旋回波T1加权(3D T1SPACE)序列。分析梗死供血区血管动脉粥样硬化斑块的存在情况,分别测量斑块最狭窄层面的狭窄程度、重构指数以及斑块强化情况;计量资料的组间比较采用t检验或Mann-Whitney U检验,计数资料的组间比较采用χ2检验,P0.05为差异有统计学意义。结果 41例病人中,SPI 14例(34.1%),DPI27(65.9%)例。SPI组中,共13例(92.9%)病人存在颅内动脉粥样硬化斑块,DPI组有15例(55.6%),SPI病人颅内动脉粥样硬化斑块的发生率高于DPI病人(P=0.038);SPI病人管腔狭窄程度大于DPI病人(71.20%±29.46%和44.01%±28.24%,P=0.019),两组间重构指数和斑块强化情况无统计学差异(P=0.865,0.538)。结论 DPI可能由小血管疾病或载体动脉斑块堵塞穿支引起,而SPI主要由大动脉粥样硬化疾病引起,这两种梗死模式具有不同的管腔狭窄程度。     

MRI与DSA对颈动脉狭窄和粥样硬化斑块评估能力的比较

目的 探讨MRI与DSA对颈动脉粥样硬化患者血管狭窄及粥样硬化斑块病变特点评估能力的差异.方法 46例缺血性脑血管疾病患者,超声发现颈动脉粥样硬化斑块后分别行颈动脉MRI及DSA检查.颈动脉MR检查序列包括三维时间飞跃法(3D TOF)、T1WI、T2WI、质子密度加权成像( PDWI)及增强T1WI;颈动脉DSA检查分别摄取颈动脉的正位像和侧位像.观察颈动脉分叉处管腔的狭窄程度和斑块的病变特征,包括纤维帽的状况、斑块内出血和钙化.计算Kappa值分析MRI和DSA对血管狭窄程度判断结果的一致性;应用配对卡方检验检测两种方法对溃疡斑块的检出差异.结果 89支血管的MR图像质量均满足诊断要求.MRI显示血管狭窄程度的M(范围)为50％(16％～78％),DSA显示为47％(7％～73％),二者具有很好的一致性(Kappa值为0.882,P＜0.01).MRI发现34支血管具有斑块纤维帽破溃,DSA发现10支血管具有溃疡斑块(x2=20.346,P＜0.01).此外,MRI发现37支血管有斑块内出血,71支血管有斑块内钙化,而DSA均不能显示.结论 MRI可以准确判断颈动脉的狭窄程度,在显示溃疡斑块、斑块内出血以及钙化方面较DSA更具优势.     

3.0T MRI 3D Space序列对颅脑动脉斑块出血的诊断应用

目的探讨磁共振可变翻转角的三维快速自旋回波(3D-sampling perfection with application optimized contrast using different flip angle evolutions, 3D-SPACE)序列检测大脑中动脉斑块内出血(intraplaque hemorrhage, IPH)的成像情况及其诊断价值。方法选取我院就诊的脑动脉粥样硬化的患者100例,所有患者均接受常规MRI检查、3D序列亮血时飞法MR血管成像(time-of-flight magnetic resonance angiography, TOFMRA),同时接受3D-SPACE序列检查。根据常规序列(T₁WI、T₂WI、3D TOF、T₁WI-CE)图像综合评估IPH,并根据患者的临床、影像学结果对所有患者进行评估,将患者分为有症状组和无症状组。对比两组患者3D-SPACE序列评估斑块信号的高低情况,同时对比3D-SPACE及常规MRI各序列对IPH的评估效果。结果有症状组72例患者中通过3D...     

Calcified carotid atherosclerotic plaque is associated less with ischemic symptoms than is noncalcified plaque on MDCT

OBJECTIVE: Risk assessment based on plaque vulnerability would be valuable in the management of asymptomatic carotid stenosis. The purpose of this study was to compare plaque morphology in symptomatic and asymptomatic patients with significant extracranial carotid artery stenosis using MDCT angiography. MATERIALS AND METHODS: We identified 31 patients with greater than 60% carotid artery stenosis on MDCT angiography using the criteria of the North American Symptomatic Carotid Endarterectomy Trial Collaborators. We analyzed plaque density by blinded review in Hounsfield units in the atherosclerotic plaques of 15 symptomatic and 21 asymptomatic stenotic vessels for classification as soft, intermediate, or calcified. Data were analyzed using multiple logistic regression. RESULTS: Even with age, traditional cardiovascular risk factors, and treatment taken into account, we found that calcified plaques were 21 times less likely to be symptomatic than noncalcified plaques (95% confidence interval for odds ratio, 0.003, 0.749; p = 0.030). No significant predictive value was found between soft (p = 0.23) or intermediate (p = 0.18) plaque morphology for the occurrence of symptoms. CONCLUSION: MDCT angiography may help risk-stratify patients with asymptomatic carotid artery stenosis. Extracranial carotid artery calcified plaques causing stenosis are significantly less likely to be symptomatic and thus may be more stable than noncalcified plaques. This finding may have implications for the interpretation of calcification of atherosclerotic plaque in other vascular beds.     

Gadolinium Enhancement of Atherosclerotic Plaque in the Middle Cerebral Artery: Relation to Symptoms and Degree of Stenosis

BACKGROUND AND PURPOSE:High-resolution MR imaging can depict intracranial arterial atherosclerotic plaques. Our aim was to evaluate the relationship between the degree of enhancement of MCA plaques on contrast-enhanced high-resolution MR imaging and ischemic stroke and stenosis severity.MATERIALS AND METHODS:This study enrolled 36 patients diagnosed with moderate-to-severe atherosclerotic MCA stenosis. A contrast-enhanced T1-weighted volume isotropic turbo spin-echo acquisition sequence was acquired for assessing plaque enhancement. Plaque-to-CSF contrast ratio was calculated after the signal intensity of plaques at the stenotic segment was measured. Univariate comparison and multivariate logistic regression analyses were performed for symptomatic and asymptomatic groups to assess the relationship between symptomatic stenosis and independent variables, including plaque-to-CSF contrast ratio, degree of stenosis, and clinical risk factors. Plaque-to-CSF contrast ratio was compared between the moderate and severe stenosis groups.RESULTS:Twenty-one patients had symptomatic MCA stenosis, and 15 had asymptomatic stenosis. The plaque-to-CSF contrast ratio was significantly higher in the symptomatic group than in the asymptomatic group (63.6 ± 10.6% versus 54.1 ± 13.5%, respectively; P < .05). The degree of stenosis also differed significantly between the 2 groups (P < .05). Multivariate analysis revealed that the degree of stenosis was the only independent predictor of ischemic stroke symptoms. The plaque-to-CSF contrast ratio of severe stenosis was significantly higher than that of moderate stenosis (66.8 ± 8.7% versus 55.9 ± 12.8%, respectively; P < .05).CONCLUSIONS:Plaque enhancement was significantly higher in patients with symptomatic plaques and may have been affected by the degree of stenosis. A difference in plaque enhancement according to the degree of stenosis has implications for understanding the development of intracranial atherosclerotic plaques.

Intracranial atherosclerotic disease (ICAD) is now considered the most common cause of ischemic stroke worldwide.^1,2 It is a challenge for many clinicians to assess vulnerable regions of intracranial artery stenosis by using in vivo methods. As a result, there has been a recent increase in interest in techniques to depict the state of the intracranial artery wall by using high-resolution MR imaging (HR-MRI) with a high magnetic field.Inflammation increases vulnerability to plaque rupture by facilitating neovascularization within the plaque and increasing endothelial permeability. Strong contrast enhancement of arterial plaques on MR imaging suggests the presence of a vascular supply and increased endothelial permeability, which facilitate the entry of contrast agents from the blood plasma.^3–6 Several studies have shown that gadolinium (Gd) enhancement of extracranial carotid plaques on MR imaging is associated with plaque neovascularization or increased levels of serum inflammatory markers such as C-reactive protein.^7–10 An association between carotid plaque enhancement and clinical symptoms has been observed in several recent investigations by using Gd-enhanced MR imaging.^9,11In contrast to the numerous investigations that have been performed on the carotid artery, only a few studies performed on a small number of patients have focused on the clinical significance of Gd enhancement of plaques in the setting of ICAD.^12–14 These studies identified a significant association between plaque enhancement on ICAD and ischemic events. However, there is some debate about whether contrast enhancement is a good predictor of intracranial stenosis in ischemic stroke. Klein et al¹⁵ expressed doubt about the relationship between plaque enhancement and stroke because they found stationary enhancement of basilar plaques regardless of the time elapsed after an acute event.Several factors are known to be related to ischemic stroke in the territory of the stenotic segment.^16,17 In particular, the severity of stenosis is a strong predictor of subsequent stroke in the territory of the symptomatic stenotic artery. To assess whether Gd enhancement of plaques at the stenotic segment is valuable as a predictor of ischemic stroke, an unbiased assessment of the influence of other independent factors, including the degree of stenosis, should be undertaken. Thus, the purpose of this study was to evaluate whether Gd enhancement of plaques in ICAD is associated with clinical symptoms, independent of other predictive factors for ischemic stroke risk.