磁敏感加权成像对急性脑梗死动脉血栓的诊断价值

目的:探讨磁敏感加权成像(SWI)技术对急性脑梗死动脉血栓的诊断价值。材料与方法:20例急性期脑梗死患者均在3.0T MR成像系统上行常规MRI、DWI、MRA和SWI序列。采用最小密度投影(mIP)观察颅内动脉血栓情况。结果:20例急性脑梗死病变中MRA显示有8例发生一侧大脑中动脉闭塞,9例大脑中动脉呈不同程度狭窄,3例MRA未见异常。急性梗死灶均位于患侧责任血管供血范围内。在20例患者中,有11例在SWI序列显示大脑中动脉内血栓,其中10例发生在大脑中动脉水平段或分支起始部,1例发生在大脑中动脉分支远端,与MRA图像动脉阻断区位置大致吻合。SWI对血栓的显示阳性率为55%。在正常血管及颅内狭窄的非责任血管内SWI均未显示动脉血栓。结论:SWI技术对急性脑梗死动脉血栓的诊断和指导治疗中具有重要的价值,可作为检测急性脑梗死血栓存在的主要检查序列。     

磁敏感加权成像在缺血性脑卒中的应用研究

目的探讨SWI技术在对缺血性脑卒中（脑梗死）诊断中的临床应用价值。方法18例急性和亚急性期脑梗死患者均在3.0TMR成像系统上行常规MRI、扩散加权成像（DWI）、MRA和磁敏感加权成像（SWI）,11例同时行灌注加权成像（PWI）检查。7例行静脉注射Gd-DTPA增强扫描,3例同时行1HMRS检查。SWI采用新的高分辨率3D-GRASS序列,图像后处理采用GE公司Advantage workstations AW4.2工作站和最小密度投影,获得脑静脉血管图。结果18例脑梗死病变在DWI图像上均显示高信号,16例MRA可见脑内动脉血管不同程度狭窄或闭塞（包括1例颈内动脉闭塞）。11例PWI显示梗死区脑血流灌注异常,9例灌注减低,2例灌注增高。SWI见10例梗死区静脉血管减少,2例完全缺失,5例静脉血管分布正常,1例增多;其中3例合并出血,1例显示左侧大脑中动脉内血栓,与MRA图像动脉阻断区位置一致。结论磁共振SWI技术在急性脑卒中的诊断和指导治疗中起着越来越重要的作用,特别是SWI在急性期脑出血检测和潜在的评价脑组织可存活性方面有重要价值。     

磁敏感加权血管成像与动脉自旋标记成像在急性脑梗死责任血管及血栓显示中的应用价值

目的探讨磁敏感加权血管成像(susceptibility weighted angiography,SWAN)与动脉自旋标记成像(arterial spin labeling,ASL)对急性脑梗死责任血管及血栓显示的临床应用价值。材料与方法收集2015年1月至2017年6月于我院经临床和影像学证实的30例大脑中动脉严重狭窄或闭塞所致急性期缺血性脑卒中患者,采用GE 3.0 T超导磁共振成像(magnetic resonance imaging,MRI)扫描仪进行常规序列、磁共振血管成像(magnetic resonance angiography,MRA)、SWAN和ASL检查,通过软件后处理得到MRA、SWAN最小密度投影图和脑血流量(cerebral blood flow,CBF)伪彩图,观察责任血管及血栓的显示情况。结果在30例患者中,SWAN提示大脑中动脉责任血管及血栓25例,CBF伪彩图提示大脑中动脉M1段血流瘀滞或缓慢23例,两种显示方法与MRA显示结果具有较好的一致性。结论 SWAN联合ASL对急性脑梗死责任血管部位及血栓成分的显示具有重要的临床应用价值。     

磁敏感加权成像对脑梗死的诊断价值

目的探讨磁敏感加权成像(SWI)对脑梗死的诊断价值。材料与方法30例患者在3.0 T MR成像系统行常规MRI、扩散加权成像(DWI)和SWI,20例同时行MR血管成像(MRA),19例行静脉注射Gd-DTPA增强扫描。将SWI采集的原始数据传输到GE AW4.4工作站离线处理,得到校正相位图(CPI)和磁化率加权图。手动测量脑梗死区及水肿区与正常对照区的CP值,采用t检验进行比较,以P0.05为差异有统计学意义。结果 30例脑梗死在DWI上表现为高信号,15例MRA图像可见大脑前、中、后动脉不同程度的狭窄或闭塞。5例SWI上可见大脑中动脉内血栓,与MRA图像显示的区域相一致;21例SWI上病灶内合并出血,CT发现9例,T1WI仅发现2例;SWI显示15例梗死区静脉血管增多,6例静脉血管分布正常,9例静脉血管分布减少。梗死区与正常对照区的CP值分别为-0.021±0.006、-0.006±0.005,差异有统计学意义(t=-2.359,P0.05);水肿区与正常对照区的CP值分别为-4.853±0.005、-1.868±0.003,差异有统计学意义(t=-2.172,P0.05)。结论 SWI对脑梗死急性期并发的出血及静脉血管分布的显示具有常规MRI无可替代的优势,对脑梗死急性期治疗具有重要的指导作用;并且校正相位图可以进行定量分析。     

对比三维多回波T2*血管成像与三维时间飞跃法MR血管成像诊断大脑半球梗死患者颅内大血管病变

目的 探讨三维多回波T2^*血管成像(3D SWAN)诊断大脑半球梗死患者颅内大血管病变的价值。 方法 对63例单侧脑梗死患者(起病时间为3 h~8天)行常规MR、DWI、3D SWAN及三维时间飞跃法MR血管成像(3D TOF MRA)检查,分析3D SWAN检测的颅内大动脉(包括大脑中动脉和颈内动脉颅内段)异常低信号,与3D TOF MRA显示的异常(中断、闭塞、狭窄)进行比较,判断两种方法对显示动脉异常的一致性,并计算Kappa值。 结果 3D TOF MRA共显示28条大脑中动脉、9条颈内动脉中断、闭塞或狭窄,而3D SWAN则显示其中30条动脉出现异常低信号,3D SWAN与3D TOF MRA对显示大脑中动脉和颈内动脉颅内段的异常具有很好的一致性(Kappa值为0.867,P＜0.05)。 结论 3D SWAN对诊断脑梗死患者大脑中动脉和颈内动脉颅内段异常有较高价值,分析3D SWAN动脉内异常低信号的特点有助于进一步判断3D TOF MRA显示的动脉中断、闭塞、狭窄的原因。     

烟雾病的MR成像及MR血管造影表现

目的评价磁共振成像(MRI)和磁共振血管造影(MRA)对烟雾病的诊断价值.方法对7例烟雾病患者均行MRI和MRA检查.结果 MRI表现:脑实质改变包括脑梗死5例,脑室轻度扩大2例,局部脑萎缩1例,7例均见双侧基底节区异常血管流空影. MRA均见不同程度的颈内动脉分叉以上狭窄或闭塞,其中双侧颈内动脉狭窄5例,单侧颈内动脉狭窄2例;大脑中动脉狭窄14支,大脑前动脉狭窄12支,大脑后动脉狭窄10支;5例同时显示异常血管网.结论 MRI及MRA可良好显示烟雾病异常血管,尤其是MRA可作为烟雾病诊断的首选检查方法.     

磁共振弥散加权成像诊断急性脑梗死30例分析

目的评价磁共振弥散加权成像(DWI)技术在诊断急性脑梗死中的临床应用价值。方法回顾性分析30例急性脑梗死患者的MRI检查资料,其中超急性期10例,急性期12例,亚急性期8例。均行常规TSE T1加权像(WI)、TSET2WI、FLAIR T2WI及SE-EPI DWI扫描,其中6例行3D时间飞行磁共振血管造影术(TOF MRA)。结果 30例DWI均清晰显示相应神经体征分布区的梗死灶,DWI对病灶的显示范围、对比度均明显优于TSE T1WI、TSE T2WI、FLAIR T2WI序列。6例行TOF MRA检查,其中2例大脑中动脉M2段完全闭塞,2例大脑前动脉主干闭塞,1例大脑后动脉闭塞,1例大脑中动脉远侧分支减少。结论 DWI在急性脑梗死的诊断中具有重要作用,结合常规TSE T1WI、TSE T2WI、FLAIR T2WI的信号变化,对判断患者脑缺血的时间有很大帮助。     

早期血管检查对急性脑梗死诊治的临床意义

目的通过回顾性分析静脉溶栓及血管内介入治疗急性脑梗死的临床实例,探讨早期血管检查对急性脑梗死诊治的临床意义。方法选取2015年8月至2018年8月该院收治的298例急性脑梗死患者作为观察对象,入院时间窗内给予静脉溶栓治疗,治疗过程中行头颈CTA检查,头颈CTA发现明确血管闭塞立即改用血管内介入治疗。结果 298例研究对象经头颈部CTA检查提示,138例(46.31%)存在颅内大血管狭窄/闭塞。其中颈内动脉狭窄18例;大脑中动脉M1段闭塞39例,狭窄33例;大脑中动脉M2段闭塞30例,大脑后动脉闭塞18例。160例不存在颅内大血管闭塞/狭窄事件。298例患者均行静脉溶栓治疗,治疗后症状好转212例,有效率为71.1%;86例静脉溶栓后疗效均不佳,时间窗内(6h)进行血管内介入治疗的患者46例,血管内治疗后有效人数32例,有效率为69.57%。结论急性脑梗死患者溶栓过程中,应尽早完善头颈部血管检查,明确是否存在大血管闭塞事件,以便于早期启动血管内介入治疗,保障患者预后。     

超声与磁共振血管成像在急性颈内动脉闭塞中的应用

目的：探讨超声、磁共振血管成像（MRA）对急性颈内动脉闭塞的诊断价值。方法：采用彩色多普勒（CDFI）、经颅多普勒（TCD）结合MRA筛查急性单侧颈内动脉闭塞56例患者,用TCD、MRA评价颅内动脉的脑血流动力学变化并与DSA进行比较。结果：颈内动脉闭塞发生在颅外段46例,颅内段10例。后交通动脉显示率MRA高于TCD（P＜0.05）;眼动脉参与的侧支循环显示率TCD高于MRA（P＜0.01）;TCD联合MRA显示侧支动脉与DSA之间无显著性差异。患侧大脑中动脉峰值流速和搏动指数均明显低于健侧（P＜0.001）。结论：超声与MRA能够很好显示急性ICA闭塞后颅内血流动力学变化和侧支循环状态。超声检查方便快捷,可作为首选方法。超声联合MRA可替代或减少有创的DSA。     

MRI血管成像与增强血管成像对后循环缺血的诊断价值

目的 探讨MRI血管成像(magnetic resonance angiography,MRA)与增强MRI血管成像(contrast-enhanced MRA,CE-MRA)诊断后循环缺血疾病的价值。方法 回顾性分析50例后循环缺血患者MRA及CE-MRA检查结果,比较2种方法图像质量、狭窄及闭塞血管数目差异。结果 CE-MRA的图像质量良好率(76%)高于MRA检查(46%)(P<0.05);CE-MRA检查椎-基底动脉多发性血管病变的阳性率48%(24/50)高于MRA检查28%(14/50)(P<0.05);CE-MRA显示椎动脉、基底动脉和大脑动脉后狭窄率分别为78%、30%、28%,MRA则显示狭窄率分别为62%、20%、18%,二者比较差异均有统计学意义(P<0.05)。结论 MRA及CE-MRA均可为后循环缺血提供诊断依据,但CEMRA诊断效能优于常规MRA检查。     

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。     

Susceptibility-diffusion mismatch correlated with leptomeningeal collateralization in large vessel occlusion stroke

ObjectiveTo investigate the relationship between asymmetric prominent hypointense vessels (prominent vessel sign, PVS) on susceptibility-weighted imaging (SWI) and leptomeningeal collateralization in patients with acute ischemic stroke due to large vessel occlusion.MethodsWe retrospectively enrolled patients with M1 segment occlusion of the middle cerebral artery who underwent emergency magnetic resonance imaging and digital subtraction angiography within 24 hours from stroke onset. The extent of PVS on SWI was assessed using the Alberta Stroke Program Early CT Score (ASPECTS). Leptomeningeal collateralization on digital subtraction angiography images was assessed using the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) scale. Spearman’s rank correlation test was performed to explore the correlation of ASITN/SIR scores with SWI-ASPECTS and SWI-diffusion-weighted imaging (DWI) mismatch scores.ResultsThirty-five patients were enrolled. There was no significant correlation between SWI-ASPECTS and ASITN/SIR scores. However, SWI-DWI mismatch scores were positively correlated with ASITN/SIR scores.ConclusionThe range of PVS on SWI did not closely reflect the collateral status, while the range of SWI-DWI mismatch was significantly correlated with the leptomeningeal collateralization. In patients with acute anterior circulation stroke due to large vessel occlusion, larger SWI-DWI mismatch was associated with better leptomeningeal collaterals.     

Application of MAGnetic resonance imaging compilation in acute ischemic stroke

BACKGROUNDSynthetic magnetic resonance imaging (MRI) MAGnetic resonance imaging compilation (MAGiC) is a new MRI technology. Conventional T1, T2, T2-fluid-attenuated inversion recovery (FLAIR) contrast images, quantitative images of T1 and T2 mapping, and MAGiC phase sensitive inversion recovery (PSIR) Vessel cerebrovascular images can be obtained simultaneously through post-processing at the same time after completing a scan. In recent years, studies have reported that MAGiC can be applied to patients with acute ischemic stroke. We hypothesized that the synthetic MRI vascular screening scheme can evaluate the degree of cerebral artery stenosis in patients with acute ischemic stroke.AIMTo explore the application value of vascular images obtained by synthetic MRI in diagnosing acute ischemic stroke.METHODSA total of 64 patients with acute ischemic stroke were selected and examined by MRI in the current retrospective cohort study. The scanning sequences included traditional T1, T2, and T2-FLAIR, three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA), diffusion-weighted imaging (DWI), and synthetic MRI. Conventional contrast images (T1, T2, and T2-FLAIR) and intracranial vessel images (MAGiC PSIR Vessel] were automatically reconstructed using synthetic MRI raw data. The contrast-to-noise ratio (CNR) values of traditional T1, T2, and T2-FLAIR images and MAGiC reconstructed T1, T2, and T2-FLAIR images in DWI diffusion restriction areas were measured and compared. MAGiC PSIR Vessel and TOF MRA images were used to measure and calculate the stenosis degree of bilateral middle cerebral artery stenosis areas. The consistency of MAGiC PSIR Vessel and TOF MRA in displaying the degree of vascular stenosis with computed tomography angiography (CTA) was compared.RESULTSAmong the 64 patients with acute ischemic stroke, 79 vascular stenosis areas showed that the correlation between MAGiC PSIR Vessel and CTA (r = 0.90, P < 0.01) was higher than that between TOF MRA and CTA (r = 0.84, P < 0.01). With a degree of vascular stenosis > 50% assessed by CTA as a reference, the area under the receiver operating characteristic (ROC) curve of MAGiC PSIR Vessel [area under the curve (AUC) = 0.906, P < 0.01] was higher than that of TOF MRA (AUC = 0.790, P < 0.01). Among the 64 patients with acute ischemic stroke, 39 were scanned for traditional T1, T2, and T2-FLAIR images and MAGiC images simultaneously, and CNR values in DWI diffusion restriction areas were measured, which were: Traditional T2 = 21.2, traditional T1 = -6.7, and traditional T2-FLAIR = 11.9; and MAGiC T2 = 7.1, MAGiC T1 = -3.9, and MAGiC T2-FLAIR = 4.5.CONCLUSIONThe synthetic MRI vascular screening scheme for patients with acute ischemic stroke can accurately evaluate the degree of bilateral middle cerebral artery stenosis, which is of great significance to early thrombolytic interventional therapy and improving patients’ quality of life.     

三维动脉自旋标记与磁敏感加权血管造影评价急性缺血性脑血管病颅内动脉狭窄北大核心CSCD

目的评价三维动脉自旋标记(3D-ASL)明亮血管征(BVS)及磁敏感加权血管造影(SWAN)磁敏感血管征(SVS)诊断急性缺血性脑血病(AICVD)颅内动脉狭窄的价值。方法对101例AICVD患者采集颅脑3D-ASL及SWAN图像,以Kappa检验评价观察者间诊断BVS和SVS的一致性。以CT血管造影(CTA)结果为标准(39例阳性),评价BVS与SVS检出颅内动脉狭窄的效能;根据动脉狭窄位置分为大动脉狭窄亚组(n=16)和中小动脉狭窄亚组(n=23),比较BVS与SVS检出大动脉狭窄与中小动脉狭窄的一致性及其诊断差异。结果观察者间判断BVS及SVS的一致性高(Kappa均≥0.8,P均<0.05)。3D-ASL显示BVS阳性30例、阴性71例,SWAN显示SVS阳性23例、阴性78例;根据BVS及SVS诊断颅内动脉狭窄的敏感度、特异度和准确率分别为74.36%、98.39%及89.11%和56.41%、98.39%及82.18%。BVS与SVS判断颅内大动脉狭窄的一致性良好(Kappa=0.61,P=0.01),诊断差异无统计学意义(P>0.05);BVS与SVS诊断颅内中小动脉狭窄的一致性中等(Kappa=0.43,P=0.01),而BVS阳性率(82.61%,19/23)显著高于SVS(56.52%,13/23)(P<0.05)。结论BVS与SVS诊断AICVD颅内动脉狭窄的效果均较好,二者对大动脉狭窄诊断效能相近,BVS对中小动脉狭窄更优。     

磁敏感加权成像在显示脑梗死血栓中的临床应用价值

目的：探讨磁敏感加权成像（Susceptibility-weighted imaging，SWI）对脑梗死血管内血栓监测的敏感性及其临床应用价值。方法：对36例（男19例，女17例，年龄20~83岁，平均65岁）急性脑梗死（临床症状出现24h以内）患者行SWI及随访检查。观察脑梗死血管内的血栓显示及显示程度，得出相应的临床NIHSS评分，并进行相关统计学分析。结果：有27例显示血栓存在，占75%，其中明显显示（血栓长度>3cm）17例，轻度显示（血栓长度<3cm）10例。大面积脑梗死的血栓显示程度与临床NIHSS评分的改变具有明显相关性（rs=0.782，P<0.01）。结论：SWI能敏感监测急性大面积脑梗死的血栓形成，并根据显示程度预测临床发展趋势，对临床治疗和预后判断起到一定的指导作用。     

磁敏感加权成像诊断慢性大脑中动脉狭窄或闭塞

目的 利用SWI评价慢性大脑中动脉(MCA)狭窄或闭塞患者相应供血区域的脑氧代谢,检出易损脑组织。方法 对单侧慢性MCA重度狭窄或闭塞患者11例(患病组)和性别、年龄与之相匹配的正常人10名(正常对照组)行TOF-MRA及SWI检查,选取相同大小的ROI测量,并比较患者患侧、健侧以及正常对照组两侧脑组织的相位弧度值及SWI信号值。结果 患者患侧、健侧、正常对照组左侧及右侧的相位弧度值分别为(6.00±2.10)×10^-3、(11.66±3.52)×10^-3、(12.08±2.86)×10^-3、(10.51±2.30)×10^-3(F=13.48,P<0.05),SWI信号值分别为194.29±28.08、238.33±24.76、245.05±8.76、233.06±11.66(F=13.36,P<0.05),差异均有统计学意义。患侧相位弧度值及SWI信号值均低于健侧及正常对照组(P<0.05)。患病组患者中2例大脑后动脉侧支循环丰富区域(枕叶为主)SWI信号及相位弧度值高于健侧。结论 SWI能间接反映慢性缺血脑组织氧摄取分数升高及脑血流量降低,可代替CT或MR灌注成像评价MCA狭窄或闭塞患者缺血范围及缺血程度,指导临床治疗。     

Monitoring and imaging the clot during systemic thrombolysis in stroke patients

Intravenous thrombolysis is the only approved treatment for acute ischemic stroke when administered within the first 3 h of stroke onset. Response to systemic thrombolysis depends on several factors including the location of arterial occlusion, clot characteristics and, ultimately, the embolic source. In the last few years, tremendous progress has been made, resulting in the widespread implementation of noninvasive neurovascular techniques. These imaging modalities are being increasingly performed in the acute stroke setting, without substantial delay, in a large number of centers worldwide. Transcranial Doppler ultrasound provides a unique opportunity to assess several aspects of clot dissolution by means of continuous monitoring of recanalization during and after tissue plasminogen activator administration. This approach allows for the evaluation of patients at the bedside and in real time due to the commencement, timing, speed and degree of artery reopening in addition to allowing the documentation of reocclusion after successful recanalization. Gradient refocused echo susceptibility vessel sign (GRE SVS) magnetic resonance imaging may be particularly useful for the identification of an intravascular thrombus during the acute phase of ischemic stroke; GRE SVS may represent a surrogate of clot composition and differential response to thrombolysis. The increasing availability of advanced neurovascular techniques may, in the near future, improve the design of stroke trials. The capability of these techniques to assess not only tissue viability but also key aspects regarding susceptibility to thrombolysis such as location, amount, composition, and age of the offending clot may improve the safety and efficacy profile of thrombolytic therapy for acute ischemic stroke.