高分辨颈动脉粥样硬化斑块磁共振成像

高分辨颈动脉磁共振成像(high-resolution carotid magnetic resonance imaging,HRCMRI)在评价活体颈动脉粥样硬化斑块方面是一种有价值的检查技术。以前很长一段时间内,人们以动脉管腔狭窄的严重性作为衡量动脉粥样硬化病变程度的主     

症状性缺血性脑卒中颈动脉斑块成分的 高分辨MRI分析

目的应用高分辨MRI(HRMRI)探讨颈动脉斑块不同成分在症状性缺血性脑卒中病人中的危险性。方法选取2016年1月—2017年6月于我院行超声检查发现存在颈动脉斑块的病人50例,其中女21例,男29例,年龄43~77岁,平均(61.62±7.96)岁。依据病人近3个月来是否发生过与患侧颈动脉相关的缺血性脑卒中临床症状分为有症状组(22例,存在斑块血管40支)及无症状组(28例,50支),所有病人行3.0 T HRMRI以评估颈动脉血管及斑块内成分。采用χ~2检验或t检验对2组病人的临床资料、斑块成分及血管管腔狭窄程度进行比较,采用logistic回归分析缺血性脑卒中病人症状的独立危险因素。结果检出存在斑块纤维帽破溃(FCR)的血管,症状组15支,检出率为37.5%,无症状组8支,检出率为16.0%,症状组FCR的检出率高于无症状组(P0.05)。检出斑块内出血(IPH)的血管,症状组21支,检出率为52.5%,无症状组15支,检出率为30.0%,症状组IPH的检出率高于无症状组(P0.05)。检出存在斑块钙化(CA)的血管,症状组15支,检出率为37.5%,无症状组13支,检出率为26.0%,2组间检出率差异无统计学意义(P0.05)。症状组管腔狭窄程度为57.64%±13.36%,无症状组为53.86%±11.19%,2组间管腔狭窄程度差异无统计学意义(t=1.460,P=0.148)。FCR在症状性缺血性脑卒中危险性最高(OR=3.012),IPH危险性次之(OR=2.478)。结论 HRMRI可以分析斑块内成分,而这些成分是缺血性脑卒中临床症状发生的危险因素,是斑块易损性的表现。     

缺血性脑血管病患者颈动脉病变与糖代谢的相关性研究

目的对缺血性脑血管病患者颈动脉病变与糖代谢相关性进行分析。方法观察对象选自2011年3月～2012年12月来我院就诊的234例缺血性脑血管病患者,以所有患者的检查结果及疾病史为依据将其分为3组：糖耐量正常组（NGT组）59例,合并糖耐量减低组（IGT组）85例,合并糖尿病组（T2DM组）90例。对患者的基本情况及生化指标等进行比较,影响因素的筛选采用多元线性回归进行分析。结果0）IGT组、T2DM组患者与NGT组比较,其具有明显较多的患者例数,具有较高的吸烟例数比例、合并高血压例数比例及具有较高的BMI、WHR及颈动脉粥样斑块积分（P〈0．05）;将T2DM组患者的以上观察指标与IGT组进行比较,其组间也具有显著性差异（P〈0．05）。②IGT组、T2DM组患者与NGT组比较,其FBG、PBG、CRP检测值明显较高（P〈0．05）;将T2DM组患者的以上生化指标与IGT组进行比较,其组间也具有显著性差异（P〈0．05）。③缺血性脑血管病颈动脉病变的影响因素如下：高血压、吸烟、FBG、PBG、CRP、BMI、WHR。结论颈动脉病变发生过程中糖代谢异常为其独立危险因素,影响颈动脉病变的危险因素还包括高血压、吸烟、BMI、WHR、CRP。     

颈动脉粥样斑块3T MR高分辨成像和MRA诊断

目的:应用3.0T MR高分辨管壁成像和MR血管造影在体显示颈动脉粥样斑块,探讨MR对颈动脉斑块的诊断价值。方法:经彩超检查证实的症状性颈动脉狭窄37例,所有病例行管腔MRA和管壁高分辨MR检查,MR检查序列包括3DTOF、DIR T1WI、T2WI、PDWI和MRA。其中,17例检查前1周内行CT血管造影检查,9例患者检查后1周内行颈动脉内膜剥脱术。根据颈动脉内膜剥脱术手术部位,将获得的病理标本与MR图像逐层对照,研究斑块脂质成分、纤维成分和纤维帽、斑块钙化、出血和脂质坏死池等MR表现,探讨斑块变性的MR表现及其病理基础。结果:37个病例共发现52条颈动脉分叉处斑块,其中,管腔轻度狭窄24条(46.1%),中度狭窄19条(36.5%),重度狭窄7条(13.5%),闭塞2条(3.9%)。斑块钙化21条(40.4%)、无钙化斑块31条(59.6%);31条软斑块中纤维成分为主斑块8条(15.6%),有明显脂质核心斑块23条(44.2%);其中,伴斑块出血5条(10%)、脂质坏死核心3条(6%),纤维帽撕裂(溃疡或纤维帽撕裂)3条(6%)。相对于胸锁乳突肌,脂质坏死池在TOF、T1WI、PDWI、T2WI均呈显著高信号,钙化在各序列均呈低信号。斑块内出血的信号与出血的时间有关,新鲜出血各序列表现为点、结节或片状高信号,亚急性出血或者陈旧出血的信号与出血时间长短有关。结论:颈动脉MRA和管壁高分辨成像是评估颈动脉斑块风险性的有效手段,无创性MRA可以显示颈动脉斑块的狭窄程度;管壁高分辨成像可以直接显示斑块纤维帽、斑块内结构和成分,预测斑块脱落的风险性。     

缺血性脑血管病颈动脉狭窄15例影像诊断

目的　评价颈动脉狭窄无创性影像学检查方法的临床应用价值 ,探讨颈动脉狭窄与缺血性脑血管病之间的联系。材料与方法　对 15例 3 0支颈动脉行多普勒超声 (DUS)、磁共振血管造影 (MRA)及头部CT、MRI检查。其中 5例同时行颈动脉CT血管造影 (CTA) ,4例与DSA对照 ,6例颈动脉重度狭窄者行颈动脉内膜切除术。结果　 15例 3 0支颈动脉 ,轻度狭窄 ( <3 0 % ) 8支 ,中度狭窄 ( 3 0 %～ 69% ) 6支 ,重度狭窄 ( 70 %～ 99% ) 8支 (均为一侧 ) ,闭塞 2支 ,未见狭窄 6支。 8支颈动脉重度狭窄者狭窄侧腔隙性脑梗死 5例 ,狭窄对侧皮层梗死 1例 ,双侧脑梗死 1例 ,未见异常 1例。颈动脉闭塞侧大脑中动脉分布区脑梗死 2例。CTA显示硬化斑块 3例。结论　颈动脉狭窄与脑梗死的发生、发展密切相关。DUS、MRA、CTA结合使用能够在颈动脉狭窄的筛选、诊断、监测中发挥重要作用。     

缺血性脑血管病颈动脉粥样硬化与血流动力学等相关因素关系分析

目的应用超声多普勒技术研究缺血性脑血管病患者颈动脉粥样硬化与其它相关危险因素包括血流动力学之间的关系。方法将242例患者行颈动脉超声检查,按照颈总动脉内膜-中层厚度（IMT）分为两组：IMT〈1.0mm组及IMT≥1.0mm组,并进行颈总动脉内径（D）、最大流速（Vmax）、最大剪切率（shearrate,SR）及年龄、血压、血脂、血糖等指标的比较。结果IMT≥1.0mm组患者的年龄、斑块数、总胆固醇（TC）及甘油三酯（TG）均高于IMT〈1.0mm组,IMT与年龄（P〈0.01）、总斑块数（P〈0.01）及空腹血糖（P〈0.05）呈正相关,IMT≥1.0mm组颈总动脉内径扩大,剪切率降低,峰值流速（Vs）则无显著差异,IMT与收缩期峰值流速及剪切率呈负相关,与颈总动脉内径呈正相关。结论年龄、TC、TG的升高,剪切率的降低是颈动脉粥样硬化的重要危险因素。     

颈动脉粥样硬化斑块MRI成像

动脉粥样硬化是威胁人类健康的一类严重疾病,脑缺血性卒中与颈动脉粥样硬化密切相关。本文回顾MRI成像技术在颈动脉粥样硬化斑块检测中的应用。     

缺血性脑血管病患者颈动脉粥样硬化与胰岛素抵抗的相关性研究

目的 :应用彩色多普勒超声检测颈动脉粥样硬化 ,确定缺血性脑血管病与胰岛素抵抗之间的关系。方法 :颈内动脉系短暂脑缺血发作患者 5 0例 ,脑梗塞患者 70例 ,根据糖耐量试验分为胰岛素抵抗组与非胰岛素抵抗组 ,分别应用超声检测颈动脉粥样硬化情况。结果 :胰岛素抵抗组颈动脉异常率 78% ,非胰岛素抵抗组颈动脉异常率为 4 0 .5 % ,P <0 .0 5 ,两组间有显著性差异。结论 :缺血性脑血管病患者胰岛素抵抗与颈动脉粥样硬化密切相关 ,表明胰岛素抵抗是缺血性脑血管病的一个重要的危险因素     

Comparison of Doppler ultrasound, magnetic resonance angiographic techniques and catheter angiography in evaluation of carotid stenosis

AIM: To compare the accuracy of ultrasound and two magnetic resonance (MR) angiographic techniques with catheter angiography in assessing atherosclerosis at the carotid bifurcation.MATERIALS AND METHODS: Forty patients with symptomatic carotid stenosis were studied by Doppler ultrasound, time-of-flight MR angiography, contrast-enhanced MR angiography and conventional catheter angiography. The degree of stenosis found on ultrasound and MR angiography was compared with the results of catheter angiography. Four different assessment methods were conducted for the MR angiographic data. Kappa, sensitivity and specificity (with confidence intervals) values were calculated for the US and MR angiography results compared to catheter angiography.RESULTS: Catheter angiography showed 12 internal carotid artery occlusions (15%), 34 severe (44%), 12 moderate (15%) and 20 mild stenoses (26%), using NASCET criteria.Ultrasound showed 65% sensitivity and 95% specificity in detecting surgically amenable lesions, whilst the MR angiographic techniques had sensitivities varying from 82-100%, and specificities from 95-100%.A moderate kappa value was calculated for the US data, whilst all MR techniques were found to show very good agreement with catheter angiography.CONCLUSION: This data suggests that MR angiography is more accurate than Doppler ultrasound in defining surgical lesions and has comparable accuracy to catheter angiography. The use of contrast-enhanced MR angiography is useful in certain situations but is not essential in all cases.     

Effects of doubling and tripling the spatial resolution in standard 3D contrast-enhanced magnetic resonance angiography of carotid artery disease

PURPOSE: To determine whether three-dimensional (3D) contrast-enhanced MR angiography (CE-MRA) of carotid artery disease may be more effective when performed at double or triple the spatial resolution of the present common clinical standard at 1.5T. MATERIALS AND METHODS: A total of 110 consecutive patients with suspected carotid artery disease were imaged with elliptical centric 3D CE-MRA. The total acquisition time was increased from the standard clinical protocol of 21 seconds up to 60 seconds in 10-second steps, with corresponding voxel volume reductions from 0.95 mm(3) down to 0.35 mm(3). Quantitative and blinded qualitative measurements were then performed to determine the preferred imaging time. RESULTS: In patients with significant stenosis, the 40-second acquisition with 0.53-mm(3) voxels produced significantly sharper images of the carotid bifurcation than the 21-second standard using 0.95-mm(3) voxels, but did not have a significant effect in patients without disease. CONCLUSION: In patients with carotid artery stenosis, decreasing the voxel volume to 0.5 mm(3) by increasing the scan time from 21 to 40 seconds resulted in sharper depiction of the carotid stenosis. Further decreases in voxel volume, by extending the acquisition time further, did not improve the vessel depiction due to both signal-to-noise ratio (SNR) and sharpness losses.     

短暂性脑缺血发作时磁共振血管成像病变特点

 目的 探讨短暂性脑缺血发作（transient ischemic attacks,TIA）时磁共振血管成像病变特点。方法 选取我院收治的60例TIA患者,行磁共振血管成像检查颅内动脉、颈部动脉,分析患者颅颈部供血动脉病变特点、狭窄情况。结果 磁共振检查发现脑供血动脉狭窄患者53例(88.33%),未见异常者7例（11.67%）。其中,颈内动脉系统发现病变者40例(75.47%),椎基底动脉系统发现病变者13例（24.53%）。不同动脉系统的病变在颅内外的分布无统计学差异（χ²=4.94,P=0.08470）。53例发生狭窄病例中,共有病变动脉92支,其中轻度狭窄20支,中度32支,重度38支,2支闭塞;按发生支数依次排序为颈内动脉、大脑中动脉、椎动脉、颈总动脉、基底动脉、大脑前动脉起始段、大脑后动脉。结论 磁共振技术诊断TIA客观,综合患者临床情况对于制定治疗方案具有重要的临床意义。     

大脑中动脉狭窄的磁共振血管成像与数字减影血管造影的对照研究

目的 探讨磁共振血管成像(MRA)在大脑中动脉狭窄或闭塞病变中的诊断价值.方法 35例缺血性脑血管病患者先后行MRA及DSA检查,以DSA为金标准,分析MRA对不同程度大脑中动脉狭窄的诊断价值.结果 35例患者70支大脑中动脉中,MRA显示正常血管28支,病变血管42支,病变部位47处,MRA与DSA诊断符合53处,符...     

Asymptomatic middle cerebral artery stenosis diagnosed by magnetic resonance angiography

We reviewed 1440 MRA studies to identify patients with middle cerebral artery stenosis (MCAS). We identified 99 cases, and after reviewing the clinical records, classified 28 as asymptomatic MCAS (AMCAS), a prevalence of 2%. Suspected stroke was the most frequent indication for MRA. Follow-up was available for 21, mean 46.7 months (range 2.4–75.6 months). One stroke occurred in the AMCAS territory (5%), other strokes in five patients (24%). There were five deaths in patients with MCAS; age >69 ( P =0.045) was the only associated risk factor. This study suggests that patients in whom MRA is performed and shows AMCAS may be at increased risk of strokes in any vascular distribution or of death.Presented in part as an abstract at the 27 ^th International Stroke Meeting, San Antonio, Texas, February 2002 and the 54 ^th American Academy of Neurology Meeting, Denver, Colorado, April, 2002     

Proton magnetic resonance spectroscopy in patients with symptomatic unilateral internal carotid artery / middle cerebral artery stenosis or occlusion

Purpose:

To explore the value of proton magnetic resonance spectroscopy imaging (¹H‐MRSI) in patients with stenosis or occlusion of the internal carotid artery (ICA) / middle cerebral artery (MCA).

Materials and Methods:

Fifty noninfarcted patients with stenosis or occlusion of unilateral ICA/MCA were included in our study. In the meantime, 25 patients with cerebral infarction and 25 healthy control subjects were enrolled. All patients and healthy control subjects underwent ¹H‐MRSI. Cerebral metabolic changes were studied in the noninfarcted patients and compared with the infarcted patients as well as healthy control subjects.

Results:

In 50 noninfarcted patients N‐acetylaspartate (NAA) decreased and choline increased in the ischemic hemisphere compared with the contralateral side and control subjects. Lactate peaks were observed in 12 patients. The metabolic changes were relatively slight but were associated with metabolic disruption in infarcted patients. There were relationships between metabolic abnormalities and neurological status of the noninfarcted patients.

Conclusion:

¹H‐MRSI can demonstrate abnormal metabolic changes in cerebral tissues with no infarction, while with ICA/MCA may show stenosis or occlusion at an early stage, which may help guide treatment decisions and preoperative evaluation. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.     

Magnetic resonance angiography of extracranial carotid and vertebral arteries,including their origins: comparison with digital subtraction angiography

Summary Although carotid bifurcation stenoses are not the only lesions of the extracranial cerebral arteries, magnetic resonance angiographic (MRA) studies to date have concentrated on the carotid bifurcation. We compared digital subtraction angiography of the extracranial portions of the cerebral arteries with MRA using an ordinary body coil, the time-of-flight method, and multiple transverse slabs which covered the arteries down to the aortic arch. Twenty-two patients (15 with arteriosclerotic diseases, 4 with aortitis, and 3 with tumours) had MRA using a 1.5 T magnet system with a three-dimensional fast imaging with steady state precession (FISP) technique. Thirty-nine carotid and 39 vertebral arteries were assessed by three radiologists with regard to stenoses or occlusions, graded as normal, mild (<30%), moderate (30–60%) or severe (>60%) stenosis, or occluded. Grading corresponded well in 81%; stenoses appeared more marked on MRA in 14% and were seen less clearly on MRA in 5%. When 26 carotid bifurcations were assessed separately, grading corresponded well in 95%. MRA is the only method which can display the whole course of the extracranial carotid and vertebral arteries non-invasively and satisfactorily.     

DWI、MRA在急性脑缺血中的联合诊断价值

目的探讨磁共振弥散加权成像（DWI）与磁共振血管成像（MRA）在急性期脑缺血中的联合诊断价值。方法收集经临床和影像学确诊为急性脑梗死的患者40例,所有患者行常规MRI、FLIAR、DWI及MRA检查。对MRA原始图像进行最大密度投影（MIP）重建,选取病灶中心和健侧相应部位8×8像素大小区域,测定各自的表观扩散系数（ADC）,并计算rADC值。结果 40例患者的DWI图像均显示与临床症状及体征相符的病灶,尤其是在超急性期,病灶具有较高的信号强度和清晰度。MRA检查均获得清晰血管图像,结果显示动脉硬化3例,动脉狭窄或闭塞28例;40例中,24例大面积病灶的血管病变阳性率为100%。DWI显示病灶解剖定位均与MRA上血管异常解剖定位有较好的一致性。结论 DWI对脑梗死超急性期、急性期均有很高的敏感性,MRA对颅内大血管及其部分分支的狭窄或闭塞情况均能很好地显示。通过DWI和MRA联合扫描进行比较,可以对应显示同一区域脑实质和脑血管情况,进一步判定责任血管。     

Atherosclerosis of the carotid artery: Evaluation by magnetic resonance angiography

Carotid artery atherosclerotic plaques (APs) can lead to brain ischemia, an event shown to correlate with both the degree of stenosis and the composition of the AP. Currently, accurate estimates of stenosis can be obtained by either x-ray angiography or three-dimensional time of-flight (TOF) magnetic resonance angiography (MRA). Our purpose was to determine whether three-dimensional TOF MRA images could also provide information on plaque location, morphology, and composition. Seven pre-endarterectomy patients underwent three-dimensional TOF MRA. After endarterectomy, plaque histology was evaluated. Three-dimensional TOF MRA images contained sufficient soft tissue contrast to differentiate the plaques from the surrounding tissues in all cases. Estimation of plaque morphology had 80% correlation with histology. Finally, intraplaque hemorrhage and calcification were depicted as regions of moderately high and very low intensity, respectively. These preliminary results suggest that three-dimensional TOF MRA may be useful in studying the development and progression of carotid atherosclerosis.     

Magnetic resonance angiography of the carotid arteries using three different techniques: accuracy compared with intraarterial x-ray angiography and endarterectomy specimens

PURPOSE: To compare three different magnetic resonance angiography (MRA) techniques with x-ray angiography and endarterectomy specimens. MATERIALS AND METHODS: Twenty-one patients underwent x-ray angiography, three-dimensional time-of-flight (TOF) focusing on the carotid bifurcation, high-resolution (HR) contrast-enhanced (CE) MRA, and time-resolved CE MRA. Stenoses of internal carotid arteries were evaluated by three independent observers on identical projection of x-ray angiography and MRA. Maximum stenosis grades on MRA were assessed additionally and correlated with endarterectomy specimens in 12 cases. RESULTS: Sensitivity for the detection of severe stenoses was excellent (100%) for all MRA techniques, and specificity was superior for three-dimensional TOF (96.7%) compared with HR CE MRA (80.6%) and time-resolved CE MRA (83.9%). The correlation between x-ray angiography and MRA for all stenoses was slightly superior for three-dimensional TOF and HR CE MRA compared with the time-resolved technique (kappa = 0.87 and 0.86 vs. 0.84). The same trend was seen for the interobserver agreement and for the correlation with endarterectomy specimens. Eleven up to 17 stenoses (depending on the MRA technique) were graded higher using additional projections. CONCLUSION: Three-dimensional TOF MRA yielded even more accurate results than HR CE MRA in grading of stenoses near the carotid bifurcation. Therefore, a combination of both methods seems to be advantageous.