颈动脉斑块易损性对冠状动脉狭窄严重程度的预测价值

目的超声评估颈动脉斑块卒中风险等级与冠状动脉病变严重程度关系,探讨颈动脉斑块易损性预测冠状动脉病变临床价值。方法选取117例冠心病患者行颈动脉超声检查,按照斑块性质分为易损斑块组与稳定斑块组,按照管腔狭窄程度分为轻度狭窄组与中度以上狭窄组,分别比较两组患者冠状动脉狭窄严重程度的Gensini评分差异度。评价每位患者颈动脉斑块卒中风险等级,比较不同风险等级组冠状动脉狭窄严重程度的Gensini评分差异度。结果颈动脉易损斑块组Gensini评分明显高于颈动脉稳定斑块组。颈动脉管腔轻度狭窄组(30%)与中度以上狭窄组(≥30%)的Gensini评分差异无统计学意义。颈动脉斑块高、极高度风险等级组冠脉Gensini积分明显高于低、中度风险组,有统计学意义。结论颈动脉斑块性质及斑块发生缺血性脑卒中风险等级在一定程度上能够推测冠状动脉硬化狭窄严重程度。     

急慢性脑卒中及TIA相关的MCA斑块的磁共振形态学研究

目的运用高分辨磁共振(HR-MRI)管壁成像技术,以症状性大脑中动脉(middle cerebral artery,MCA)粥样硬化症患者为研究对象,定性和定量分析斑块的形态学特征,探索MCA斑块与卒中相关的高危HR-MRI特征。方法收集2013年4月~2014年5月之间在我院就诊的症状性MCA动脉粥样硬化症患者,利用3.0 T MR仪行头颅3D TOFMRA、双侧MCA的HR-MRI和全脑扩散加权成像(DWI),其中HR-MRI包括T_2WI、T_1WI、STIR和对比增强T_1WI。将患者分为陈旧性脑梗死组、短暂性脑缺血发作(TIA)组和急性脑梗死组。对hr MRI的定性分析是以同序列眼外肌信号为参考将斑块分为等、高、低及混杂信号四种类型;定量测量最小管径和斑块厚度,计算斑块负荷、管腔重塑率和斑块强化率。结果有141例患者纳入本研究,平均(53.6±10.1)岁,男96例(68.09%),其中陈旧性脑梗死组15例(10.64%),TIA组86例(60.99%),急性脑梗死组40例(28.37%)。根据HR-MRI,T_1WI、T_2WI和STIR序列中急性脑梗死组的混杂信号斑块的数量和比例均明显多于TIA组和陈旧性脑梗死组,差异均有统计学意义(P0.0001;P0.0001;P=0.0006)。定量分析发现,急性脑梗死组的最小管径明显小于TIA组和陈旧性脑梗死组(P0.0001);陈旧性和急性脑梗死组的斑块厚度显著大于TIA组(P=0.0003);急性脑梗死组的斑块负荷和管腔重塑率最大(P=0.0021;P=0.0846),且急性脑梗死组的斑块强化率的平均值也大于其他两组(P=0.0413)。结论利用HR-MRI管壁成像技术可实现对症状性MCA粥样硬化斑块的形态及信号进行无创性评估。急慢性脑卒中相关的MCA斑块在多序列HR-MRI中呈现不同的形态学特征。     

MR颅颈一体化高分辨血管壁成像定量分析在脑卒中相关血管床斑块负荷中应用

目的：探究MR颅颈一体化高分辨血管壁成像定量分析在脑卒中相关血管床斑块负荷中应用。方法：选取2018年12月—2020年12月院内诊治缺血性脑卒中患者100例作为研究组,无症状危险人群50例和健康志愿者50例作为对照组,均接受平扫及增强颅颈一体化血管壁成像。记录研究组缺血侧和非缺血侧颈动脉血管壁参数,并以是否发生脑组织不可逆死亡分为良好预后组与不良预后组,分析2组缺血侧颈动脉管壁参数、对疾病预后价值、与美国国立卫生研究院卒中量表（NIHSS）相关性。随访对照组2年,以是否发生缺血性脑卒中分为疾病组和正常组,分析2组颈动脉管壁参数及其预测价值。结果：缺血侧管腔面积小于非缺血侧,血管总面积、管壁面积、管壁标准化指数大于非缺血侧（P<0.05）。良好预后组管腔面积大于不良预后组,血管总面积、管壁面积、管壁标准化指数小于不良预后组（P<0.05）。颈动脉管壁参数联合检测缺血性脑卒中预后ROC曲线下面积AUC(0.824)最大。研究组管腔面积与NIHSS呈负相关关系（P<0.05）。疾病组管腔面积小于正常组,血管总面积、管壁面积、管壁标准化指数大于正常组（P<0.05）。...     

复发急性缺血性脑卒中患者大脑中动脉斑块的高分辨率MRI研究

目的利用3.0 T高分辨磁共振(HR-MRI)研究复发急性缺血性脑卒中患者大脑中动脉斑块形态特征。材料与方法回顾性分析77例责任血管为大脑中动脉的急性缺血性脑卒中患者资料,其中初发患者36例(初发组),复发患者41例(复发组),所有患者均行3.0 T高分辨磁共振斑块成像(扫描序列包括TOF-MRA,头颅常规DWI,责任血管轴位T1WI、T2WI及T1WIGd-DTPA增强)。对比分析初发组与复发组急性缺血性脑卒中患者责任血管管腔狭窄率、最小管腔面积、斑块负荷、斑块强化率、T1WI及T2WI斑块信号强度指数。结果复发组患者大脑中动脉管腔狭窄率(P=0.002)、斑块负荷(P=0.005)、斑块强化率(P=0.037)均明显高于初发组,最小管腔面积(P=0.001)明显小于初发组。复发组斑块T2WI信号强度指数大于初发组(P0.001),而T1WI信号强度指数两者无明显差异(P=0.245)。结论高分辨率磁共振可以有效评估复发急性缺血性脑卒中患者大脑中动脉斑块的形态特征,综合评价斑块特征可为临床提供参考以助于预防脑卒中复发。     

自发性头颈动脉夹层HRMRI与缺血性卒中的相关性分析

目的 分析自发性头颈动脉夹层(spontaneous cervicoce-rebral artery dissection,SCAD)在高分辨力磁共振成像(high-resolution magnetic resonance imaging,HRMRI)中的影像学特征与急性缺血性卒中的相关性。 方法 对23例确诊为自发性头颈动脉夹层的患者进行HRMRI检查。排除心源性卒中及图像质量差者。由 2 名放射科医生对HRMRI 影像学特征进行双盲分析,评价内容包括内膜瓣、壁内血肿及夹层动脉瘤等。将每个患者划分为颈动脉系统及椎动脉系统4支血管节段进行观察分析。比较卒中组(发生急性缺血性卒中)和非卒中组(未发生急性缺血性卒中)SCAD患者HRMRI特征差异。 结果 最终21例患者纳入研究。84个血管节段中共诊断27个节段存在动脉夹层,其中累及颈内动脉系统11个节段、椎动脉系统16个节段。27个血管节段中11个节段存在供血区急性缺血性卒中。卒中组的管腔狭窄所占比例(54.5%)较非卒中组(19.2%)大,差异有统计学意义(P＜0.001),卒中组的壁内血肿(72.7%)所占比例较非卒中组(1.4%)大,差异有统计学意义(P＜0.001)。 结论 HRMRI存在管腔狭窄及壁内血肿的SCAD患者更易发生急性缺血性卒中。     

颈动脉粥样硬化与缺血性卒中危险分层相关性分析

目的观察急性缺血性卒中患者的颈动脉粥样硬化与卒中复发风险分层的关系。方法采用Essen卒中风险评分量表(ESRS)对82例急性缺血性卒中患者的危险因素评估后分为ESRS≥3分组(40例)和ESRS 0～2分组(42例),经彩色多普勒超声仪对两组进行评估,比较两组颈动脉粥样硬化特征和程度。结果 ESRS≥3分组与ESRS 0～2分组相比,ESR≥3分组中高龄、高血压、糖尿病和本次卒中之前有TIA或缺血性卒中的比例明显较高(P<0.05)。ESRS≥3分组颈动脉内-中膜厚度(IMT),斑块(尤其多发斑块)发生率,脂质性、钙化性斑块发生率,中、重度粥样硬化发生率明显高于ESRS 0～2分组(P<0.05)。经多因素非条件Logistic回归分析,颈总动脉IMT≥1.0 mm,脂质性、钙化性斑块,颈动脉粥样硬化程度与ESRS≥3分组卒中复发的危险因素成正相关。结论颈动脉粥样硬化与缺血性卒中复发高危风险密切相关。颈总动脉IMT、颈动脉粥样硬化的严重程度可作为卒中高危复发风险的预测指标。     

高分辨率磁共振评价单侧大脑中动脉闭塞管腔形态特征及脑梗死类型

目的利用高分辨率磁共振(high-resolution magnetic resonance imaging,HR-MRI)评价单侧大脑中动脉M1段闭塞两种不同的管腔形态特征及对应脑梗死类型的差异。材料与方法回顾性分析因缺血性脑卒中住院诊断为单侧大脑中动脉M1段闭塞患者资料,所有患者均在发病1周内行HR-MRI及头颅扩散加权成像(diffusion weighted imaging,DWI)检查,观察大脑中动脉M1段闭塞管腔形态特征及头颅DWI上脑梗死类型。依照HR-MRI上闭塞管腔的形态学特征将患者分为斑块形成组与非斑块形成组;DWI上脑梗死类型分为单发脑梗死、多发脑梗死、无脑梗死灶。结果 44例患者纳入分析,斑块形成组30例,非斑块形成组14例。斑块形成组闭塞位置位于近端16例,远端14例,非斑块形成组闭塞部位为近端13例,远端1例,两组闭塞部位差别有统计学意义(P=0.025,χ~2=4.99),非斑块形成组闭塞部位多为M1段近端。斑块形成组与非斑块形成组单发性脑梗死分别为11例和5例,多发性梗死分别为15例和2例,无梗死灶分别为4例和7例,两组脑梗死类型差别有统计学意义(P=0.016,χ~2=8.29),斑块形成组脑梗死类型多为多发性脑梗死,而非斑块组多为单个脑梗死或无梗死灶。结论高分辨MRI对大脑中动脉闭塞管腔管壁形态特征评价具有重要价值,闭塞管腔内是否有斑块与主干周围有无侧支形成可能是大脑中动脉闭塞后不同脑梗死类型差异的一个重要原因。     

缺血性卒中合并2型糖尿病患者的颈动脉斑块的研究

目的:研究缺血性卒中合并2型糖尿病(type 2 diabetes mellitus,T2DM)患者的颈动脉斑块的临床特点和影响因素。方法:将2013年7月—12月收治的185例缺血性卒中患者分为T2DM组(n=72)及非T2DM组(n=113),用超声检查颈动脉斑块,其中22例患者行颈动脉CT血管造影(computed tomographic arteriography,CTA)检查;分析糖、脂代谢相关指标与颈动脉斑块大小的相关性。结果:T2DM组颈动脉斑块的发生率、性质、大小及颈动脉内中膜厚度(intima-media thickness,IMT)与非T2DM组比较差异有统计学意义(P0.05)。影响颈动脉斑块大小的主要因素为是否患T2DM、餐后2 h血糖(2 h postprandial blood glucose,2 h PBG)、稳态模型胰岛素抵抗指数(homeostatic model assessment for insulin resistance,HOMA-IR)、空腹血糖(fasting blood glucose,FBG)、低密度脂蛋白胆固醇(low density lipoprotein-cholesterol,LDL-C),P0.05。超声和CTA对22例患者颈动脉管腔的狭窄程度的检查结果差异有统计学意义(P0.05)。结论:缺血性卒中患者颈动脉斑块的大小与是否患T2DM、2 h PBG、HOMA-IR、FBG和LDL-C相关,合并T2DM时颈动脉斑块发生率升高,易损斑块比例升高。超声检查可作为颈动脉斑块筛查的首选方法,CTA更易于显示斑块的性质及管腔的狭窄程度。     

颅内动脉狭窄斑块特征与缺血性卒中的关系

目的应用高分辨率磁共振成像(high resolution magnetic resonance imaging,HR-MRI)技术分析颅内动脉粥样硬化狭窄患者的斑块特征与发生缺血性卒中事件的关系。材料与方法回顾性分析44例HR-MRI检查的颅内动脉粥样硬化狭窄患者的斑块情况,通过三维时间飞跃法磁共振血管成像(3D-time of flight magnetic resonance angiography,3D-TOF MRA)检查,按管腔狭窄程度将患者分为轻度狭窄组、中度狭窄组和重度狭窄组,根据斑块是否导致缺血性卒中及发生缺血性卒中距HR-MRI检查时间,将斑块分为急性/亚急性期责任斑块组、慢性期责任斑块组、非责任斑块组,比较3组的动脉粥样硬化危险因素(性别、年龄、吸烟史、饮酒史、高血压、糖尿病史、血糖、总胆固醇、高密度脂蛋白、低密度脂蛋白)以及斑块特征(管腔狭窄程度、斑块强化程度)。结果 44例患者中急性/亚急性期责任斑块数目为29个,慢性期责任斑块数目为20个,非责任斑块数目为17个。急性/亚急性期责任斑块组、慢性期责任斑块组、非责任斑块组的管腔狭窄程度、斑块强化程度差异有统计学意义(P0.05);而3组的动脉粥样硬化危险因素差异均无统计学意义。结论颅内动脉粥样硬化狭窄患者斑块强化程度和管腔狭窄程度与是否发生缺血性卒中具有相关性;明显强化的、导致管腔严重狭窄的斑块稳定性更差,更容易发生缺血性卒中。     

3D-SNAP高分辨磁共振成像技术评价颅内动脉夹层的价值研究

目的探讨三维同步非增强血管造影和斑块内出血(threedimensionalsimultaneous noncontrast angiography and intra plaque hemorrhage,3D-SNAP)高分辨磁共振成像技术对颅内动脉夹层的诊断价值。材料与方法连续收集2015年1月至2018年3月陕西省人民医院神经内科43例后循环短暂性脑缺血发作(transientischemicattack,TIA)或脑梗死患者,其中颅内动脉夹层18例,非动脉夹层25例,所有患者均采用PhilipsIngenia 3.0 T MRI获取TOF-MRA、T1WI-VISTA、T2WI、3D-SNAP、CE-T1WI成像,双盲分析各序列颅内动脉夹层征象。采用卡方检验、独立样本t检验分析夹层组与非夹层组临床基本资料以及夹层组各序列影像学特征;利用受试者工作特征(receiveroperating characteristic,ROC)曲线比较各序列对颅内动脉夹层的诊断效能。结果 (1)夹层组年龄较非夹层组低,差异有统计学意义(P<0.05),两组间性别、血压、糖尿病、吸烟差异均无统计学意义。(2)6例患者在TOF-MRA、T2WI、T1WI-VISTA、SNAP及CE-T1WI成像序列同时显示夹层瘤样扩张、真假腔、壁内血肿、内膜瓣征象;颅内动脉夹层壁内血肿、双腔征及内膜瓣显示率高分辨MRI各序列比较差异有统计学意义(P<0.05),SNAP显示壁内血肿最敏感,CE-T1WI显示双腔征、内膜瓣征最敏感。(3) TOF-MRA、T2WI、T1WI-VISTA、3D-SNAP、CE-T1WI、SNAP联合CE-T1WI成像序列诊断颅内动脉夹层ROC曲线下面积分别为0.663、0.492、0.729、0.741、0.752、0.824。结论 3D-SNAP高分辨磁共振成像技术无创性、有效评价颅内动脉夹层具有无限的潜力和广阔的前景。     

Comparison of carotid arterial morphology and plaque composition between patients with acute coronary syndrome and stable coronary artery disease: a high-resolution magnetic resonance imaging study

The purpose of this study was to evaluate the differences in carotid arterial morphology and plaque composition between patients with acute coronary syndrome (ACS) and patients with stable coronary artery disease (SCAD). Twenty-eight patients (12 ACS patients and 16 SCAD patients) underwent carotid high-resolution MRI examination using a 3.0-Tesla (3.0T) MRI scanner. The indicators of carotid arterial morphology included the maximum total vessel area (Max-TVA), mean TVA, minimum lumen area (Min-LA), mean LA, maximum wall area (Max-WA), mean WA, maximum wall thickness (Max-WT), mean WT, maximum normalized wall index (Max-NWI), mean NWI, and maximum stenosis (Max-stenosis). The indicators of plaque composition included the prevalence and mean area percentage (%) of lipid-rich necrotic core (LRNC), calcification (Ca), intraplaque hemorrhage (IPH), and fibrous cap rupture (FCR). None of the indicators of carotid arterial morphology had significant differences (all P > 0.05) between the ACS and SCAD patients. The prevalence and plaque composition area percentage of LRNC, Ca, and IPH did not exhibit significant differences between the two groups. However, carotid plaques in the ACS patients presented a higher prevalence of FCR than SCAD patients (P < 0.05). This study revealed a similar carotid arterial morphology between ACS and SCAD patients. However, FCR is more common in carotid plaques with ACS than in those with SCAD. Ruptured carotid plaques may be a forewarning factor for those patients who are at high risk of ACS.     

Bilateral symmetry of human carotid artery atherosclerosis: a multi-contrast weighted MR study

The systemic nature of atherosclerotic disease may entail an association in disease severity between left and right carotid arteries. However, the etiology of plaque features in high-risk lesions is presumably attributed to local risk factors. We explored the symmetry of plaque morphology and composition across a broad range of atherosclerotic disease severities. All participants underwent carotid MR imaging on a 3.0 T scanner with a bilateral four-element phased-array surface coil. Vessel boundary and plaque components [calcification, lipid-rich necrotic core (LRNC) and intraplaque hemorrhage (IPH)] of bilateral carotid arteries were outlined. Normalized wall index (NWI) was calculated as follows: NWI?=?wall volume/total vessel volume. Carotid atherosclerosis score (CAS) was computed for plaque risk stratification. Associations of volume measurements between sides were evaluated using Pearson’s correlation. Cohen’s kappa was used to assess agreement between dichotomous variables. In the 177 participants with images of sufficient quality, there were very strong correlations between left and right lumen volumes (r?=?0.85), total vessel volumes (r?=?0.88), and strong correlations between wall volumes (r?=?0.79), mean wall thickness (r?=?0.66) and NWI (r?=?0.71), and a moderate correlation between max wall thickness (r?=?0.56) (all P?<?0.001). There were moderate between-side agreements for the presence of calcification (κ?=?0.54) and LRNC (κ?=?0.49), but only fair agreement for IPH (κ?=?0.31). The correlation of volume between left and right carotid arteries was strong for calcification (r?=?0.62, P?<?0.001) and weak for LRNC (r?=?0.39, P?<?0.001), but there was no significant correlation for IPH (r?=?0.01, P?=?0.99). Fair agreement (κ?=?0.34) for CAS between paired carotid arteries was observed. Only 16 of 47 participants with CAS?=?4 on at least one side had the same CAS on the contralateral side. Plaque morphology, calcification, and LRNC may develop symmetrically, but there is a relatively poor correlation for lipid content between sides. The weak symmetry of IPH and CAS indicates that the development of atherosclerosis into high-risk lesions may be regulated by local rather than systemic factors.     

A comparison study between 3D T2-weighted SPACE and conventional 2D T2-weighted turbo spin echo in assessment of carotid plaque

The aim of this study was to compare 3D T2-weighted sampling perfection with application optimized contrast using different flip angle evolutions (T2w SPACE) with conventional 2D T2w turbo-spin echo (TSE) in plaque imaging of carotid artery. 45 patients underwent 3.0-T MRI for carotid arteries imaging. MR sequences included T2w SPACE, T2w TSE, Time of flight (TOF) and T1-weighted (T1w) TSE. The signal intensity of intra-plaque hemorrhage (IPH), lipid-rich necrotic core (LRNC), and loose matrix (LM) were measured and their contrast ratios (CRs) against adjacent muscle were calculated. CRs from T2w SPACE and T2w TSE were compared to each other. CRs of LM, LRNC, and IPH measured on T2w SPACE were 1.74–3.04 (2.44), 0.98–1.66 (1.39), and 1.91–2.93 (2.51), respectively. CRs of LM, LRNC, and IPH on T2w TSE were 1.97–3.41 (2.44), 1.18–1.73 (1.43), and 2.26–3.75 (2.26), respectively. There was no significant difference of CR of the carotid plaques between T2w SPACE and T2w TSE (p?=?0.455). Markedly significant differences of CRs were found between LM and LRNC (p?<?0.001), and between LRNC and IPH (p?<?0.001) on T2w SPACE and T2w TSE. T2w SPACE was comparable with conventional T2w TSE in characterization of carotid plaque.     

基于临床及高分辨率血管壁MRI分析颈部动脉夹层患者发生急性缺血性脑卒中危险因素

目的 基于临床及高分辨率血管壁MRI(HRMR-VWI)分析颈部动脉夹层(CAD)患者发生急性缺血性脑卒中(AIS)的危险因素。方法 回顾性分析48例经头颈动脉HRMR-VWI诊断的CAD患者，观察其头部弥散加权成像，将27例梗死灶位于夹层血管供血区域者纳入AIS组，其余21例纳入非AIS组。采用单因素及多因素logistic回归分析评估CAD患者发生AIS的临床及HRMR-VWI相关危险因素。结果 组间男性、糖尿病及HRMR-VWI显示双腔征、腔内血栓占比，以及管壁强化程度、管腔狭窄程度差异均有统计学意义(P均<0.05)。男性、糖尿病、HRMR-VWI显示双腔征、腔内血栓、管壁2级强化及管腔重度狭窄/闭塞是CAD患者发生AIS的危险因素(P均<0.05)。男性(OR=8.77)、糖尿病(OR=21.01)及HRMR-VWI显示管壁2级强化(OR=4.21)均为CAD患者发生AIS的独立危险因素(P均<0.05)。结论 男性、糖尿病及HRMR-VWI显示管壁2级强化均为CAD患者发生AIS的独立危险因素。     

MRI定量分析颈动脉粥样硬化斑块脂质坏死核:与手术病理对照

目的 探讨MRI定量分析颈动脉斑块内脂质坏死核心（LRNC）的准确性。方法 对19例颈动脉内膜剥脱术（CEA）患者术前行MR颈动脉检查,于MRI图像和病理组织学切片上分别测量LRNC的大小,计算其所占总管壁面积的百分比,分析两者的相关性。结果 共151个MRI图像层面与患者的病理组织学区域相匹配,MRI与组织学测得LRNC占总管壁面积的百分比分别为（20.64±9.03）%和（18.65±9.49）%,两者具有中-高度相关性（r=0.69,P<0.001）。结论 MRI可定量测量颈动脉斑块内LRNC,有助于预测斑块的稳定性。     

脑卒中高危人群体质指数与颈动脉斑块的关系研究

目的 探讨体质指数（BMI）与脑卒中高危人群颈动脉斑块之间的相关性。方法 利用浙江省人民医院登记的546例脑卒中高危患者的资料,分析其BMI与颈动脉斑块发生的关系,并应用logistic回归分析不同BMI合并影响脑卒中的危险因素对形成颈动脉斑块的危险。结果 logistic回归分析显示,BMI是脑卒中患者颈动脉粥样斑块病变的独立危险因素（OR=1.653,95% CI:1.063~2.572,P=0.026）。超重组以及肥胖组合并脑卒中的相关危险因素包括年龄和高血压,糖尿病组颈动脉斑块的形成率均高于对照组（P0.05）。其中,合并高血压病史组的颈动脉粥样斑块的形成率均显著高于无高血压组,分别是对照组的2.270、3.167和3.647倍（P0.01）。结论 随着BMI升高,特别是具有脑卒中相关危险因素的人群,发生颈动脉粥样斑块的风险也明显升高。     

Quantitative evaluation of high intensity signal on MIP images of carotid atherosclerotic plaques from routine TOF-MRA reveals elevated volumes of intraplaque hemorrhage and lipid rich necrotic core

Background

Carotid intraplaque hemorrhage (IPH) and lipid rich necrotic core (LRNC) have been associated with accelerated plaque growth, luminal narrowing, future surface disruption and development of symptomatic events. The aim of this study was to evaluate the quantitative relationships between high intensity signals (HIS) in the plaque on TOF-MRA and IPH or LRNC volumes as measured by multicontrast weighted CMR.

Methods

Seventy six patients with a suspected carotid artery stenosis or carotid plaque by ultrasonography underwent multicontrast carotid CMR. HIS presence and volume were measured from TOF-MRA MIP images while IPH and LRNC volumes were separately measured from multicontrast CMR.

Results

For detecting IPH, HIS on MIP images overall had high specificity (100.0%, 95% CI: 93.0 – 100.0%) but relatively low sensitivity (32%, 95% CI: 20.8 – 47.9%). However, the sensitivity had a significant increasing relationship with underlying IPH volume (p = 0.033) and degree of stenosis (p = 0.022). Mean IPH volume was 2.7 times larger in those with presence of HIS than in those without (142.8 ± 97.7 mm³ vs. 53.4 ± 56.3 mm³, p = 0.014). Similarly, mean LRNC volume was 3.4 times larger in those with HIS present (379.8 ± 203.4 mm³ vs. 111.3 ± 122.7 mm³, p = 0.001). There was a strong correlation between the volume of the HIS region and the IPH volume measured from multicontrast CMR (r = 0.96, p < 0.001).

Conclusion

MIP images are easily reformatted from three minute, routine, clinical TOF sequences. High intensity signals in carotid plaque on TOF-MRA MIP images are associated with increased intraplaque hemorrhage and lipid-rich necrotic core volumes. The technique is most sensitive in patients with moderate to severe stenosis.     

Lower blood flow velocity, higher resistance index, and larger diameter of extracranial carotid arteries are associated with ischemic stroke independently of carotid atherosclerosis and cardiovascular risk factors

PURPOSE: To investigate the association between diameter and flow velocity of the carotid arteries and ischemic stroke. METHODS: Peak systolic velocity, end diastolic velocity, Pourcelot resistance index, blood flow volume, luminal diameter, and carotid plaque burden were measured and compared in 240 ischemic stroke (IS) patients without history of stroke, 163 chronic stable IS patients, and 236 nonstroke controls (age, >or=40 years). Data were also compared between stroke subtypes (large artery atherosclerosis, lacunar, cardioembolic, or undetermined origin). RESULTS: Acute as well as chronic stable IS patients had significantly lower flow velocities and flow volume, higher resistance index than nonstroke controls in the common carotid artery (CCA), internal carotid artery and external carotid artery, and larger common carotid artery diameter. The differences were found across all IS subtypes and in stroke patients with as well as without carotid plaque. Comparisons between these subgroups showed significant differences in end diastolic velocity, resistance index, flow velocity, and diameter that were more prominent in the CCA. After adjusting for carotid plaque and cardiovascular risk factors, the associations between the above-mentioned parameter and stroke remained significant. CONCLUSIONS: Stroke patients in acute as well as chronic stable phase appeared to have larger CCA diameters, lower carotid flow velocities and volume, and higher resistance index than nonstroke patients independently of extracranial carotid atherosclerosis. These findings need to be confirmed by a prospective study.