DWI在MCA区急性脑梗死患者诊断中的应用价值

目的探究弥散加权成像(DWI)在大脑中动脉(MCA)供血区急性脑梗死诊断中的应用价值。方法选择2016年12月～2018年12月在我院治疗的121例急性脑梗死患者作为观察对象,对所有患者进行常规MRI检查、DWI检查和磁共振血管成像(MRA)检查,观察、分析其影像学资料,并对其脑梗死区体积和脑动脉狭窄程度进行计算。结果 121例的DWI结果均能够清晰显示神经体征对应区域的梗死病灶,DWI对病灶的显示范围、对比程度均明显优于T_1WI、T_2WI。超急性脑梗死、急性脑梗死患者的患侧ADC值均明显低于健侧ADC值,超急性脑梗死患者的rADC值为60.23%,明显高于急性脑梗死(50.12%),差异比较有统计学意义(P0.05)。MRA结果显示,11例表现正常,62例MCA区主支血管影及其分支缺失,22例MCA区血管影呈现局限性狭窄、稀疏,26例的MCA区主支血管影粗细不均及狭窄,分支血管影表现为弥漫性稀疏,呈枯枝状。MCA区狭窄越严重的患者,其DWI异常区体积越大,不同MCA区域狭窄程度患者的DWI异常区体积上比较存在显著差异(P0.05)。结论 DWI在诊断MCA区急性脑梗死敏感性和特异性较高,可在发病早期快速定位病灶,在显示病灶上优于常规MRI扫描。MCA区急性脑梗死患者DWI异常区体积与其MCA区血管狭窄程度有关,可将其作为预测病程严重程度的临床指标。     

粥样硬化性大脑中动脉的高分辨率MRI成像与脑梗死的血管危险因素研究

目的应用高分辨率MRI成像(HRMRI)观察粥样硬化性大脑中动脉(MCA)的管壁结构,并分析脑梗死的血管危险因素。方法将38例MCA供血区脑梗死或短暂性脑缺血发作(TIA)患者分为梗死组与TIA组,行HRMRI检查,并寻找与脑梗死风险相关的血管危险因素。结果脑梗死组、TIA组两者比较,MCA粥样硬化斑块、斑块稳定性的差异有统计学意义。MCA管腔内存在粥样硬化斑块是脑卒中的血管危险因素。结论 HRMRI能清楚显示动脉粥样硬化性MCA的管壁,对于脑梗死发生风险的评估具有优势。     

SWI-SVS与MRA在大脑动脉闭塞评估中的应用

目的探讨磁敏感加权成像中磁敏感血管征(SWI-SVS)与MRA在显示大脑动脉闭塞中应用。方法回顾性连续纳入130例发病6h内前循环脑梗死急性期患者,均接受头部CT、MRI检查,并记录患者基线情况。对CT及MRI进行分析,记录SVS存在的情况,共有33例SWI-SVS与DSA或CTA结果对照一致。结果以DSA或CTA为参照标准,SVS、MRA对急性MCA主干闭塞的阳性率分别为54.5%(18/33),84.8%(28/33),其中SVS显示大脑中动脉远端血栓优于MRA。结论 MRA准确度高于SVS,MRA在大脑动脉闭塞中具有良好的适用性,同时SVS在显示大脑中动脉远端分支血栓具有优势,MRA在显示颈内动脉闭塞方面具有优势,因此SVS可对MRA起到辅助诊断的作用,两者具有互补作用,两者都可为急性缺血性卒中的早期诊断、治疗方式的选择及溶栓后血管再通预测提供参考依据。     

急性缺血性脑卒中磁敏感加权成像中低信号血管影的临床应用初探

目的 探讨磁敏感加权成像(SWI)中的低信号血管影在急性缺血性脑卒中(acute ischemic stroke,AIS)诊断中的临床应用价值.资料与方法 选择符合纳入标准的AIS患者11例,发病时间3～48 h,其中男性8例,女性3例,年龄28～85岁,行MRI.序列:T_1WI,T_2WI,T_2液体衰减反转恢复序列(T_2FLAIR),扩散加权成像(DWI),三维时间飞跃法磁共振血管成像(3D TOF MRA),SWI,灌注加权成像(PWI)及T_1WQI增强扫描.由3名有经验的神经放射学医师采用盲法分析MRI结果.结果 11例患者均可见大脑中动脉(MCA)供血区缺血病灶.SWI显示MCA内低信号与MRA显示的颈内动脉(ICA)、MCA血管阻塞有较好的相关性(Spearman等级相关系数ps=0.7698,P=0.0056),其预测ICA、MCA血管阻塞的灵敏性为100%,特异性为66.7%.SWI示11例中4例缺血区内可见异常的静脉血管影,PWI显示病灶体积与缺血区内出现走行僵直的静脉血管影这一征象有较好的相关性(Spearman等级相关系数ps=0.8367,P=0.0013);相对平均通过时间(rMIT)与缺血区内出现走行僵直的静脉血管影这一征象也有较好的相关性(Spearman等级相关系数ps=0.7188,P=0.0127).T_1WI增强扫描示1例可见MCA管壁强化.结论 AIS患者SWI中的低信号血管影与血栓形成及血流速度减慢有关,即其病理机制与去氧血红蛋白浓度增加有关.     

急性缺血性脑梗死动脉内溶栓临床疗效评价

目的评价尿激酶动脉内溶栓治疗急性缺血性脑梗死的临床疗效。方法对162例急性缺血性脑梗死患者应用尿激酶进行局部动脉内溶栓治疗,分析不同阻塞血管部位血管再通率和3个月后格拉斯哥预后评分(GOS)之间的关系。结果脑血管造影发现血管闭塞162例,其中颈内动脉系统闭塞119例(73.5%):颈内动脉(ICA)主干闭塞27例(16.7%),大脑中动脉(MCA)闭塞63例(38.9%),大脑前动脉(ACA)闭塞29例(17.9%);椎基底动脉(VBA)闭塞43例(26.5%)。溶栓后再通分别为11例,40.7%;49例,77.8%;20例,68.9%和23例53.5%。治疗后3个月恢复良好者90例(55.6%),预后差72例(44.4%)。颅内出血8例(4.9%);再灌注损伤73例(45.1%);再栓塞6例(3.1%)。分析后认为ICA主干、VBA动脉再通率较低,预后差;MCA、ACA再通率高,预后好;开始治疗时间血管再通率和临床疗效相关(相关系数r=0.86)。结论局部动脉溶栓可以明显改善脑梗死患者的预后;预后和开始治疗的时间、血管再通有相关性,大脑中、前动脉血管再通率高,预后较好;颈内动脉主干血管阻塞很难再通;椎基底动脉血管再通后症状有所改善;血管不能再通或并发脑出血预后较差。     

大脑中动脉M1段闭塞后动脉偏侧优势与PVS相关性研究

目的 探讨大脑中动脉(MCA)M1段闭塞后,动脉偏侧优势与突出血管征(PVS)之间的相关性,并评估PVS与患者入院当日及两周脑卒中评分量表(NIHSS)评分相关性.方法 选取2017年1月～2019年12月单侧MCA M1段闭塞的急性缺血性脑血管病患者55例,依据磁共振血管成像(MRA)提示有无同侧大脑前动脉(ACA)...     

磁共振成像技术对急性脑梗死的诊治价值

急性脑梗死最有效的治疗方法是超早期溶栓治疗。磁共振成像(MRI)技术对脑梗死后病理改变的检测敏感和相对特异，结合弥散加权成像(DWI)、灌注加权成像(PWI)及磁共振血管成像(MRA)，可以超早期发现急性缺血性卒中的病变部位、损害范围、缺血区可逆及不可逆损害区和血流灌注及过度再灌注情况，为溶栓治疗提供直观的影像学依据。     

自体血栓栓塞性兔大脑中动脉脑梗死影像学模型的建立

目的 探索建立兔自体血栓性脑梗死模型的方法 ,观察是否适合使用常规影像学设备研究.材料与方法 家兔40只,对照组10只,实验组30只.颈部正中切口,穿刺颈外动脉,实验组向颈内动脉内注射自体静脉血栓,对照组仅注射生理盐水,3h后行CT灌注(CTP)成像、MR常规及扩散加权、扩散张量成像、数字减影血管造影(DSA)检查.观察手术侧大脑中动脉(MCA)供血区的血流灌注、MR信号及血管是否异常.结果 实验组26只(86.67%)动物可见手术侧MCA区CT灌注异常、MRI异常信号及DSA上手术侧MCA闭塞,其中8只(30.77%,8/26)同时可见大脑前动脉供血区异常灌注及MR信号异常,病理学表现为Evans蓝(EB)异常染色,镜下可见急性脑梗死典型征象.对照组影像学及病理学均无异常.两组CTP灌注参数差异明显(P＜0.01或0.05).结论 自体血栓性兔大脑中动脉梗死模型制作较简单,成功率较高,各种临床型影像学设备均能显示其异常.     

磁共振弥散加权成像检查在脑梗死诊断中的应用分析

目的 分析磁共振弥散加权成像检查在脑梗死诊断中的应用.方法 将接受治疗的80例脑梗死患者随机分为磁共振(MRI)组(40例)和弥散加权成像(DWI)组(40例).其中MRI组患者给予MRI检查,DWI组患者给予磁共振弥散加权成像检查.比较两组患者序列检出情况,急性脑梗死检出情况,绘制ROC曲线评估MRI、DWI对脑梗死...     

磁敏感血管征对预测急性缺血性脑卒中静脉溶栓后血管再通的价值

目的：探讨大脑中动脉（MCA）的磁敏感血管征（SVS）对预测急性缺血性脑卒中患者静脉溶栓后血管再通的意义。方法：纳入70例发病6h 内急性前循环脑梗死患者,均接受 MRI 检查并记录患者年龄、性别、起病到首次 MRI 扫描时间、高血压史、糖尿病史、房颤史、吸烟史、溶栓前 NIHSS 评分、溶栓前后血管再通分级评分及90 d 后 mRS 评分。根据SVS 将70例患者分为 SVS 阳性组和 SVS 阴性组。计量资料的组间比较采用 Mann-Whitney U 检验;分类资料的组间比较采用χ2检验;缺血性脑卒中危险因素及 SVS 存在情况与溶栓后血管再通情况的相关性采用二分类 logistic 回归分析。结果：SVS 阳性组44例,SVS 阴性组26例。两组之间年龄、性别、起病到首次 MRI 扫描时间、高血压史、糖尿病史、房颤史、吸烟史、溶栓前 NIHSS 评分、病因分型差异均无统计学意义（P ＞0．05）。SVS 阳性组的溶栓后血管再通比例显著高于SVS 阴性组（χ2＝16．41,P ＜0．001）。结论：MCA 的 SVS 有助于预测 rt-PA 静脉溶栓后的急性缺血性脑卒中患者的血管再通情况。     

Negative Susceptibility Vessel Sign and Underlying Intracranial Atherosclerotic Stenosis in Acute Middle Cerebral Artery Occlusion

BACKGROUND AND PURPOSE:The role of MR imaging in predicting underlying intracranial atherosclerotic stenosis before endovascular stroke therapy has not been studied. Our aim was to determine the diagnostic value of the negative susceptibility vessel sign on T2*-weighted gradient-echo MR imaging for predicting underlying intracranial atherosclerotic stenosis in patients with acute MCA occlusion.MATERIALS AND METHODS:Ninety-one consecutive patients with acute stroke because of MCA occlusion underwent gradient-echo MR imaging and MRA before endovascular therapy. The negative susceptibility vessel sign was defined as an absence of a hypointense signal change within the occluded MCA on gradient-echo imaging. Underlying intracranial atherosclerotic stenosis was determined by conventional angiography. The sensitivity, specificity, predictive values, and accuracy of the negative susceptibility vessel sign for predicting the presence of underlying intracranial atherosclerotic stenosis were assessed.RESULTS:The negative susceptibility vessel sign was identified in 42 (46.1%) of 91 patients, and 18 (19.8%) patients had an underlying intracranial atherosclerotic stenosis responsible for acute ischemic symptoms. The negative susceptibility vessel sign was more frequently observed in patients with intracranial atherosclerotic stenosis than in those without it (100% versus 32.9%, P < .001). In the prediction of an underlying intracranial atherosclerotic stenosis, the negative susceptibility vessel sign had 100% sensitivity, 67.1% specificity, 42.9% positive predictive value, 100% negative predictive value, and an accuracy of 73.6%.CONCLUSIONS:The negative susceptibility vessel sign on gradient-echo MR imaging is a sensitive marker with a high negative predictive value for the presence of an underlying intracranial atherosclerotic stenosis in patients with acute ischemic stroke because of MCA occlusions. The susceptibility vessel sign can be used in decision-making when performing subsequent endovascular revascularization therapy in patients with acute MCA occlusions.

Intracranial atherosclerotic stenosis (ICAS) is one of the most common causes of ischemic stroke worldwide and is particularly prevalent in Asian, black, Hispanic, and Indian populations.^1,2 Underlying ICAS can be a hidden cause of refractory occlusions following modern mechanical thrombectomy procedures, such as stent-based thrombectomy (SBT) or manual aspiration thrombectomy in patients with acute ischemic stroke.³ Thus, preprocedural identification of underlying ICAS in patients with intracranial large-vessel occlusions is of particular importance when performing endovascular stroke therapy.On MR imaging, hypointense signal changes in the occluded MCA on gradient-echo (GRE) sequences have been described as a susceptibility vessel sign (SVS).^4,5 The pathophysiologic basis for this sign in patients with an acute MCA occlusion is a T2-shortening effect of the intracellular deoxyhemoglobin component in erythrocytes within the clot.⁴ Several researchers showed that the SVS was more commonly seen in red blood cell–dominant and mixed clots than in fibrin-dominant clots and could therefore reflect the composition of the clots.⁶ In addition, GRE SVS was observed more frequently in patients with cardiogenic embolic stroke than in those with other stroke subtypes.⁵ In contrast, the absence of the GRE SVS might be associated with a smaller clot burden or a fibrin-dominant clot that forms as a result of rupture of the underlying atherosclerotic plaque. Thus, we hypothesized that the absence of the GRE SVS despite the presence of intracranial large-vessel occlusions could indicate an underlying ICAS in patients with acute ischemic stroke within 6 hours of stroke onset, and we termed this finding the “negative SVS.” Despite the widespread use of MR imaging for the diagnosis of acute ischemic stroke, the role of MR imaging in predicting underlying ICAS before endovascular therapy has not been studied, to our knowledge. In this study, we evaluated the diagnostic value of the negative SVS on GRE imaging for the prediction of underlying ICAS in patients with acute MCA occlusion.     

Diagnostic and prognostic value of early MR Imaging vessel signs in hyperacute stroke patients imaged <3 hours and treated with recombinant tissue plasminogen activator

BACKGROUND AND PURPOSE: Analogous to the CT hyperattenuated vessel sign (HMCAS), MR imaging may show hypo- or hyperintense vessels in acute ischemic stroke (AIS) patients. We assessed the diagnostic and prognostic strength of early MR imaging vessel signs in AIS patients treated with intravenous thrombolysis (IVT) within 3 hours of the onset of symptoms. METHODS: We studied AIS patients both treated with IVT and stroke MR imaged within 3 hours of the onset of symptoms and at 2 hours and 24 hours after treatment. We assessed the presence or absence of early vessel signs (hyperintense fluid-attenuated inversion recovery sign [FLAIR HVS]; gradient-echo susceptibility vessel sign [GRE SVS]) compared with a combined MR angiography/perfusion-weighted imaging reference and their strength for predicting clinical outcome (favorable vs. poor, independent vs. dependent, or dead, death), recanalization (by clot composition and flow), and hemorrhage in uni- and multivariate analysis. RESULTS: Fifty-six patients (age range, 76 years +/- 13 years; median National Institutes of Health stroke scale score [NIHSSS], 11) met the inclusion criteria. Forty-four patients (78.6%) had a vessel occlusion at baseline; 22 of them (50%) recanalized. Nineteen patients (33.9%) suffered some form of intracranial hemorrhage (ICH), 24 patients (42.9%) had an independent outcome, 18 patients (32.1%) a favorable outcome, and 14 patients died. Compared with our combined reference for vessel status PWI/MRA, the sensitivities of CT HMCAS, FLAIR HVS, and GRE SVS were 40%, 66%, and 34%, respectively, and improved during the hours that followed. Localization was accurately reflected by FLAIR HVS but not by GRE SVS. Only NIHSSS and age were independent predictors for recanalization and all clinical outcomes in multiple logistic regression analysis. CONCLUSION: Although early vessel signs can be helpful in the diagnosis of intravascular disease, they do not independently predict recanalization, ICH, or any of the three clinical outcomes in a multivariate logistic regression model. Thrombus composition as reflected by signal intensity characteristics on GRE and FLAIR does not predict the therapeutic effect of IVT.     

磁敏感征和不对称静脉征对急性大脑中动脉闭塞患者诊断价值

目的探讨磁共振磁敏感加权成像(SWI)的动脉磁敏感征(SVS)和不对称脉静脉血管征(AVS)对急性大脑中动脉闭塞(AMCAO)引起急性缺血性卒中(AIS)体积程度的预测研究和临床价值。方法45例AMCAO患者,根据阿尔伯塔卒中计划早期CT评分为基础的改良SWI-ASPECTS评分梗死病灶侧显著组和稀疏组以及无SVS组、SVS≤20 mmm组、>21 mm组进行SWI-ASPECTS评分量化,比较患者脑梗死体积程度的差异。结果45例AMCAO患者,无SVS者11例(占24.4%),有SVS征者34例(SVS≤20 mm为19例,SVS>20 mm为15例)(占75.6%)。无SVS组、SVS≤20 mm组、SVS>20 mm组,其脑梗死体积分别为(5.11±5.913)mm^3、(22.71±33.568)mm^3和(111.51±87.352)mm^3,三组梗死体积差异有显著统计学意义(P<0.001),三组梗死SWI-ASPECTS评分差异有显著统计学意义(P<0.01)。随着SVS长度增加,SWI-ASPECTS评分呈减小趋势(经Spearman检验,r=-0.538,P<0.001);AVS稀疏组19例(占42.2%),AVS显著组26例(占57.8%),其体积分别为(103.555±80.684)mm^3和(7.413±8.224)mm^3,经Mann-Whitney U检验,稀疏组的梗死体积大于显著组,差异有显著统计学意义(Z=-5.102,P<0.001)。结论SVS是颅内动脉严重狭窄或闭塞的标志,代表了血栓的存在及血管内新鲜凝血块形成、预测栓子成分。AVS代表急性颅脑大血管闭塞的脑缺血区周围软脑膜侧支循环的形成,AVS越广泛,SVS长度越小,梗死面积越小,SWI-ASPECTS评分越高患者的侧支循环分级越高。这对于患者最终梗死体积及临床预后的评估都具有重要意义。     

Potential for the Use of the Solitaire Stent for Recanalization of Middle Cerebral Artery Occlusion without a Susceptibility Vessel Sign

BACKGROUND AND PURPOSE:Absence of the MCA susceptibility vessel sign (negative MCA susceptibility vessel sign) on gradient recalled-echo MR imaging in acute stroke is commonly associated with in situ stenosis and thrombotic occlusion. We evaluated the effectiveness and safety of the Solitaire stent as the first-line device for the recanalization of MCA occlusion with a negative MCA susceptibility vessel sign.MATERIALS AND METHODS:Thirty-eight consecutive patients presenting with acute ischemic stroke due to MCA occlusion were treated by using the Solitaire AB stent alone or combined with thrombolytic drugs. Among these patients, 11 (7 men and 4 women; median age, 70 years; range, 49–89 years) who underwent multimodal stroke MR imaging before the endovascular procedure and had no MCA susceptibility vessel sign on the initial gradient recalled-echo MR imaging were included in this study. The primary end point was the recanalization of the occluded artery evaluated by the arterial occlusive lesion score. Clinical outcome was assessed at discharge and 90 days, as was the degree of residual MCA stenosis or reocclusion.RESULTS:Successful recanalization (arterial occlusive lesion score ≥ II) without balloon angioplasty was obtained in 9 patients (81.8%). Six patients (54.5%) had an mRS score of ≤2 at 90 days. After a median of 147 days, no patient showed reocclusion on follow-up imaging. There were no symptomatic intracerebral hemorrhages.CONCLUSIONS:The Solitaire stent is a feasible tool as the first-line device for multimodal endovascular recanalization therapy in acute ischemic stroke with a negative MCA susceptibility vessel sign. It has a good rate of successful and complete recanalization and is a fast yet safe procedure.

The Solitaire stent (Covidien/ev3, Irvine, California) was initially developed as a device for assisting coil embolization of intracranial aneurysms.^1–3 However, its ability to be completely and safely retrieved after full deployment allows it to be used as a device for mechanical thrombectomy in patients with acute thromboembolic stroke. Many reputable studies have shown that entrapping and extracting the thromboembolus by using the Solitaire stent is fast and effective in vascular recanalization, especially when treating large arterial occlusions, including MCA occlusion.^4–8Thromboembolus in the MCA is known to create the MCA susceptibility vessel sign (SVS) on gradient recalled-echo (GRE) MR imaging.^9,10 This sign results from a T2-shortening effect of intracellular deoxyhemoglobin in the acute stage of a red blood cell clot.⁹ Thus, the MCA SVS is more commonly seen in red blood cell–dominant and mixed clots and can reflect the clot composition.^9,11,12 Cho et al¹² also showed that the SVS on GRE MR imaging was more commonly associated with cardioembolic stroke (77.5%) than other stroke subtypes (25.5%, P < .001). They suggested that the relatively greater thrombus burden in a cardioembolism may increase the conspicuity of SVS, so the SVS could be more frequently observed in cardioembolic stroke.In contrast to the presence of the SVS, its absence is generally associated with a small amount of thrombus; fibrin-rich thrombus, a potential target for chemical thrombolysis; or an in situ steno-occlusive lesion, which could be an indication for angioplasty.^11,12 Consequently, we can assume that mechanical thrombectomy by using the Solitaire stent could be less effective in acute ischemic stroke with a negative MCA SVS, which could represent an in situ steno-occlusive lesion. To our knowledge, there has been no report demonstrating the effectiveness of the Solitaire stent in acute ischemic stroke with a negative MCA SVS. The purpose of our study was to evaluate the effectiveness and safety of mechanical thrombectomy by using the Solitaire stent in acute ischemic stroke with a negative MCA SVS.     

MR angiography of steno-occlusive lesions of intracranial arteries: a comparative study between turbo MRA and conventional MRA]

PURPOSE: To compare the quality and diagnostic accuracy of images of intracranial steno-occlusive lesions obtained by conventional MRA and turbo MRA reconstructed using the zero-filled interpolation technique in the slice-select direction. MATERIALS AND METHODS: Eighteen patients with suspected steno-occlusive lesions of the intracranial arteries were studied with two types of three-dimensional time-of-flight angiography and conventional digital subtraction angiography. In total, 45 steno-occlusive lesions were quantitatively measured using calipers and correlated with DSA stenosis. A phantom that simulated vessels with stenosis was also imaged using the two types of MRA under the same conditions as those employed in the clinical study. RESULTS: Compared with conventional MRA, turbo MRA reduced the jaggedness of vessels and offered appearances more similar to those of DSA in the antero-posterior and lateral views. The severity of stenosis was classified into five grades based on the percentage of occlusion: not significant (0-24%), mild (25-49%), moderate (50-74%), severe (75-99%), and occlusive (100%). Neither turbo MRA nor conventional MRA showed any discrepancy from DSA above grade-1 stenosis. CONCLUSION: The advantage of turbo MRA is its ability to reduce the jaggedness of vessels on conventional MRA, and to simplify the recognition of vessel contours without prolonging acquisition time. Turbo MRA and conventional MRA have equally high diagnostic accuracy for steno-occlusive lesions.     

MR 3D-SPACE与3D-TOF序列在颅内神经血管压迫综合征的比较研究

目的：探讨 MR可变反转角的三维快速自旋回波(3D-SPACE)序列与三维时间飞跃快速扰相梯度回波(3D-TOF)序列的融合图像在颅内神经血管压迫综合征的诊断价值。方法对26例典型颅内神经血管压迫综合征的患者行3D-SPACE 序列与3D-TOF序列检查,利用2种序列图像进行不同比例融合,分别就2种序列原始图像、融合图像的影像质量及神经、血管位置关系的评价能力进行比较分析。结果本研究中,1次3D-SPACE+1次3D-TOF序列融合图像显示阳性正确例数最高(21例),对责任血管与神经关系判断与手术结果符合例数最多(P<0.05)。结论3D-SPACE序列和3D-TOF序列融合图像可以提高在颅内神经血管压迫综合征的诊断能力,并且适当比例融合图像显示神经血管关系最佳。     

三维T2*加权血管成像检测大脑中动脉磁敏感征的应用

目的探讨三维T2*加权血管成像(3DSWAN)检测缺血性脑卒中患者大脑中动脉磁敏感征的应用价值。方法回顾性分析48例大脑中动脉供血区域急性缺血性脑卒中患者MR检查的影像资料,对照分析3DTOF MRA和3DSWAN序列检测大脑中动脉磁敏感征的对应关系。并比较不同发病时间缺血性脑卒中患者大脑中动脉磁敏感征的检出率。结果大脑中动脉磁敏感征在3DSWAN序列上表现为MCA走行区域的多个连续层面上,宽度大于对侧血管管径的条状低信号;经2检验关联性分析,3DSWAN和3DTOF MRA对显示大脑中动脉磁敏感征的对应关系有统计学意义(P<0.05),Pearson关联系数C=0.740,显示两者间关联性较高;3DSWAN序列对超急性期脑梗塞患者大脑中动脉磁敏感征检出率(70%)高于非超急性期(28%),经2检验,二者之间差异有统计学意义(P<0.05)。结论 3DSWAN序列检测大脑中动脉磁敏感征可以提供缺血性脑卒中的血栓信息。     

Redistribution of cerebropetal blood flow in patients with carotid artery stenosis measured non-invasively with fast cine phase contrast MR angiography

The purpose was to evaluate the blood flow redistribution in the neck vessels of patients with internal carotid artery (ICA) stenosis. Eighty-six patients with ICA stenosis underwent contrast-enhanced magnetic resonance angiography (CEMRA) and fast 2D phase contrast (2D-PC) sequence to measure the mean blood flow (MBF) of ICA, basilar artery (BA) and middle cerebral artery (MCA). CEMRA revealed 53 severe stenoses, 45 moderate stenoses and 3 occluded vessels. Patients with a unilateral severe ICA stenosis had a significantly reduced MBF of the ICA compared to the control group; the MBF reduction of the severely stenosed ICA was less conspicuous if associated with a controlateral severe stenosis. The MBF of the BA increased significantly in the presence of the bilateral severe ICA stenosis and in the ICA occlusion. The MBF of the MCA was unchanged in the presence of various degrees of ICA stenosis. Measurement of MBF with fast PC MRA permits cerebropethal blood flow assessment and gives additional information in grading ICA stenosis. The reduced MBF of a severe ICA stenosis has to be considered with caution since it depends also on the status of the controlateral ICA and may be considered a confident parameter only in case of unilateral carotid stenosis.     

颅内高信号血管征与颈内或大脑中动脉重度病变患者发生脑缺血事件相关

目的:探讨颅内高信号血管征(HVS)与颈内动脉或大脑中动脉重度病变患者发生症状性脑缺血事件之间的相关性及其危险因素.方法:搜集颈内动脉或大脑中动脉重度病变患者96例,依据头颅磁共振液体衰减恢复信号(FLAIR)结果判断HVS,按照Alberta卒中项目早期CT评分(mASPECTS)标准对HVS进行评分(HVS-mAS...     

Middle Cerebral Artery Stenosis in Patients with Acute Ischemic Stroke and TIA in Israel

BACKGROUND AND PURPOSE:Middle cerebral artery stenosis is not frequent but a well-established cause of first and recurrent ischemic stroke. Our aim was to investigate middle cerebral artery stenosis in the biethnic (Jewish and Arab) population of patients with acute ischemic stroke and transient ischemic attack in northern Israel.MATERIALS AND METHODS:The study population included 1344 patients from the stroke data registry who had been hospitalized in the neurologic department because of acute ischemic stroke (1041) or TIA (303) and had undergone transcranial Doppler sonographic examination during the hospitalization.RESULTS:Of the 1344 patients, 120 (8.9%) were found to have MCA stenosis. The patients with intracranial stenosis were older and had more vascular risk factors (hypertension, diabetes, and hyperlipidemia) and vascular diseases (ischemic heart and peripheral vascular disease) than those without intracranial stenosis. Logistic regression analysis revealed that diabetes (P = .002) and peripheral vascular disease (P = .01), but not ethnicity, were independent and significant predictors for the presence of MCA stenosis.CONCLUSIONS:An independent and significant correlation was found between MCA stenosis and vascular risk factors (diabetes mellitus) and vascular diseases, thus emphasizing the similarity of intracranial MCA stenosis and other vascular diseases originating from atherosclerosis. There was no influence of ethnicity on intracranial stenosis in our population.

Intracranial stenosis is most commonly due to an atherosclerotic lesion of the intracranial vessels, leading to subsequent narrowing or occlusion of these vessels.^1,2 This condition is being increasingly recognized as an important and underestimated etiology in acute ischemic stroke.^3–5 Differences in the prevalence of intracranial stenosis in various populations have been reported, with the most vulnerable patients seeming to be Asians, Hispanics, and African Americans.^6–10 Because intracranial stenosis usually represents an atherosclerotic lesion, it is not surprising that there is a clear correlation between intracranial stenosis and vascular diseases and vascular risk factors.^11–15The aim of the present study was to search for possible determinants of potentially symptomatic middle cerebral artery stenosis in patients with stroke and transient ischemic attack in a biethnic (Jewish and Arab) population of northern Israel.Many studies in the literature suggest different transcranial Doppler sonography (TCD) parameters (peak systolic velocity, mean velocity) and different values as cutoffs for the diagnosis of intracranial stenosis. There are also many different definitions in the literature of intracranial stenosis (eg, “mild, moderate, and severe,” “less and more than 50%,” “50%–69% and more than 70%,” and so forth). There are still no generally accepted criteria for moderate intracranial stenosis. In this study, potentially symptomatic intracranial stenosis was defined as cases in which TCD examination showed a peak velocity in the middle cerebral artery, either left or right, of ≥140 cm/s. This value was used by some researchers as a criterion correlating with MCA stenosis of ≥50%.^3,16