脑梗死后锥体束Wallerian变性的DTI研究进展

运动通路缺血性脑卒中可导致病灶远端的锥体束发生Wallerian变性,扩散张量成像技术显示Wallerian变性不仅具有较高的敏感性和特异性,而且能在活体定量监测其演变过程,这对判断脑卒中患者的预后具有重要意义。本文主要针对脑卒中后锥体束Wallerian变性的扩散张量研究进展进行综述。     

基于DTI的脊髓型颈椎病患者皮质脊髓束逆行性损害的研究

目的:应用磁共振弥散张量成像(DTI)观察脊髓型颈椎病(CSM)患者皮质脊髓束(CST)逆行性Wallerian变性的特征,并分析其损伤程度与肢体运动功能障碍的关系。资料与方法:对28例CSM患者及28例性别和年龄相匹配的健康志愿者行常规MRI及DTI检查,分别测量位于双侧脑桥、大脑脚、内囊后肢、侧脑室体旁白质、半卵圆中心及中央前回皮层下白质的ROI的各向异性分数(FA)值和表观扩散系数(ADC)值。所有被试者均采用JOA运动评分法进行临床运动功能评分。研究各ROI的FA值及ADC值的变化,并分析其与临床运动功能评分的相关性。结果:CSM组各ROI左右两侧对称部位的FA、ADC值差异均无统计学意义(P>0.05)。与健康对照组相比,CSM患者的各平面的FA值均减低(P<0.05),半卵圆中心、内囊后肢及脑桥的ADC值升高(P<0.05)。CSM组的JOA评分较对照组减低(P<0.05),且与内囊后肢、大脑脚、脑桥处的FA值以及内囊后肢的ADC值相关。结论:DTI可以检测出CSM患者CST的继发性逆行性Wallerian变性,而且这种逆行性的神经纤维继发性变性可能与患者的运动功能受损有关。     

Water Diffusion Changes in Wallerian Degeneration and Their Dependence on White Matter Architecture

This study investigates water diffusion changes in Wallerian degeneration. We measured indices derived from the diffusion tensor (DT) and T2-weighted signal intensities in the descending motor pathways of patients with small chronic lacunar infarcts of the posterior limb of the internal capsule on one side. We compared these measurements in the healthy and lesioned sides at different levels in the brainstem caudal to the primary lesion. We found that secondary white matter degeneration is revealed by a large reduction in diffusion anisotropy only in regions where fibers are arranged in isolated bundles of parallel fibers, such as in the cerebral peduncle. In regions where the degenerated pathway crosses other tracts, such as in the rostral pons, paradoxically there is almost no change in diffusion anisotropy, but a significant change in the measured orientation of fibers. The trace of the diffusion tensor is moderately increased in all affected regions. This allows one to differentiate secondary and primary fiber loss where the increase in trace is considerably higher. We show that DT-MRI is more sensitive than T2-weighted MRI in detecting Wallerian degeneration. Significant diffusion abnormalities are observed over the entire trajectory of the affected pathway in each patient. This finding suggests that mapping degenerated pathways noninvasively with DT-MRI is feasible. However, the interpretation of water diffusion data is complex and requires a priori information about anatomy and architecture of the pathway under investigation. In particular, our study shows that in regions where fibers cross, existing DT-MRI-based fiber tractography algorithms may lead to erroneous conclusion about brain connectivity.     

卒中早期手指被动运动的脑功能磁共振成像研究

目的应用扩散张量成像及BOLD-fMRI技术观察卒中早期手指被动运动时大脑半球相关区域血氧水平的变化情况.方法采用1.5 T MR成像系统对6名早期卒中患者进行BOLD-fMRI及扩散张量成像,采用手指被动屈伸运动作为fMRI的刺激任务.结果在锥体束中断时,卒中早期健手运动时激活双侧SMC区,患手运动可激活对侧半球后顶叶皮层及同侧SMC区;锥体束较完整时健手运动时激活对侧SMC区,患手运动激活双侧SMC区、双侧后顶叶皮层.结论卒中早期可能发生运动功能通路的重构,但锥体束不同损伤情况下运动功能恢复可能存在不同的机制.DTI与fMRI联合应用将是监测和研究脑卒中后恢复的有用工具.     

弥散张量成像各向异性分数与缺血性脑卒中患者上肢运动功能的相关性

目的 探讨不同区域弥散张量成像(DTI)参数与缺血性脑卒中患者上肢运动功能恢复的关系。方法 2019年1月至12月,缺血性脑卒中患者20例接受常规药物和康复治疗3周,治疗前后,DTI测量梗死灶及对侧相应部位,患侧和健侧大脑脚、内囊后肢各向异性分数(FA),计算双侧FA比(rFA)。同时采用Fugl-Meyer评定量表上肢部分(FMA-UE)进行评定。结果 治疗后,患者FMA-UE评分显著增加(t = 9.074, P < 0.001)。梗死灶FA与rFA显著升高( t > 14.519, P< 0.001)。治疗前后各部位患侧FA和rFA差值均与FMA-UE评分差值正相关(r = 0.445~0.565, P< 0.05),以患侧内囊后肢相关性最强。结论 缺血性脑卒中,脑内FA的改变与上肢运动功能恢复相关,尤其是内囊后肢。     

针刺阳陵泉对脑梗死患者白质结构的影响

目的研究针刺阳陵泉穴后脑卒中患者白质结构的变化。方法6 例脑卒中恢复期左侧偏瘫的患者,以假穴为对照,在针刺左侧阳陵泉前后对患者进行弥散张量成像(DTI)检查,采用西门子1.5 T磁共振仪采集数据,应用FSL软件包中的基于传导束的空间统计(TBSS)方法对针刺前后的数据进行比较。结果针刺阳陵泉穴对脑白质各向异性(FA)的影响强于假穴的区域包括左侧中央前、后回,颞中、下回,辅助运动区,额下回,内囊,穹窿和双侧顶下回。这些区域中走行的纤维束有锥体束、弓状束、胼胝体纤维和皮层间联络纤维,涉及运动代偿、体感、语言和记忆等多个功能网络。结论与假穴相比,针刺阳陵泉可使脑梗死患者的白质超微结构出现变化,主要的变化区域出现在健侧半球,与多个脑功能网络相关。     

基底节区脑出血后相关神经纤维继发性损害的磁共振研究

目的:探讨应用磁共振弥散张量成像(DTI)技术动态观察基底节区脑出血后神经纤维的顺行性、逆行性变性的过程。方法:选取2011年1月-2012年6月收治的单侧基底节区出血病灶患者10例为研究组,分别在发病的第1周、1月、3月进行DTI检测,得到半卵圆中心、放射冠、内囊、大脑脚、脑桥等部位的部分各向异性图(FA)并测量其值,并与正常对照组10例比较。结果:在出血灶同侧近端纤维束行程上和远端锥体束经路上都可出现清晰可见的信号减弱区,从发病的第1周至3月FA值明显降低。结论:基底节区脑出血除了原发部位的损伤,还可以出现其近端、远端纤维的继发性变性改变。     

定量DTI在儿童脑室周白质损伤所致脑瘫中的应用

【目的】运用扩散张量成像（DTI）技术,评价脑室周脑白质损伤患儿脑白质和深部灰质的扩散特性。【方法】采用配对设计方法,对25例脑室周脑白质损伤患儿和25例正常儿童进行常规MRI和DTI检查。用Functool2和DTIStudio软件处理原始图像,得到DTI图像。分析大脑、脑干不同脑白质区域及丘脑、豆状核、尾状核头部深部灰质核团感兴趣区（ROD的平均扩散率（MD）和部分各向异性值（FA）。采用配对资料t检验统计方法检验患儿组与对照组的MD和FA有无显著性差异。【结果】与对照组相比,怠儿组脑白质损伤病灶的ROI测量显示MD显著升高和FA显著下降,患儿组锥体束内囊后肢层面FA减低具有统计学意义,患儿组深部灰质核团MD和FA差异无统计学意义。【结论】不同区域运动通路的变性,在脑室周脑白质损伤患儿的病理生理学机制中发挥重要作用。     

Altered white matter microstructure in the corpus callosum in Huntington's disease: Implications for cortical “disconnection”

The corpus callosum (CC) is the major conduit for information transfer between the cerebral hemispheres and plays an integral role in relaying sensory, motor and cognitive information between homologous cortical regions. The majority of fibers that make up the CC arise from large pyramidal neurons in layers III and V, which project contra-laterally. These neurons degenerate in Huntington's disease (HD) in a topographically and temporally selective way. Since any focus of cortical degeneration could be expected to secondarily de-afferent homologous regions of cortex, we hypothesized that regionally selective cortical degeneration would be reflected in regionally selective degeneration of the CC. We used conventional T1-weighted, diffusion tensor imaging (DTI), and a modified corpus callosum segmentation scheme to examine the CC in healthy controls, huntingtin gene-carriers and symptomatic HD subjects. We measured mid-sagittal callosal cross-sectional thickness and several DTI parameters, including fractional anisotropy (FA), which reflects the degree of white matter organization, radial diffusivity, a suggested index of myelin integrity, and axial diffusivity, a suggested index of axonal damage of the CC. We found a topologically selective pattern of alterations in these measures in pre-manifest subjects that were more extensive in early symptomatic HD subjects and that correlated with performance on distinct cognitive measures, suggesting an important role for disrupted inter-hemispheric transfer in the clinical symptoms of HD. Our findings provide evidence for early degeneration of commissural pyramidal neurons in the neocortex, loss of cortico-cortical connectivity, and functional compromise of associative cortical processing.     

Extent of pyramidal tract wallerian degeneration in the brain stem on MRI and degree of motor impairment after supratentorial stroke.

The relationship between Wallerian degeneration in the brain stem and degree of motor impairment is discussed. Using MRI we studied 172 supratentorial stroke patients, whose motor impairment was graded according to Brunnstrom stage. Wallerian degeneration was represented by a T2 high-intensity area in the brain stem, and its cross-sectional extent was measured at the cerebral peduncle level. Wallerian degeneration was detected in 99 patients (57.6%). The area of T2 high intensity was significantly correlated with Brunnstrom stage. Multiple regression analysis showed that the upper extremity stage contributed most to the visualization of Wallerian degeneration. This is partly because the pyramidal tract participates in fine and precise movement. The extent of the area of Wallerian degeneration is found to be helpful in making a prognosis with respect to motor impairment in the upper extremity.     

Visualization of peripheral nerve degeneration and regeneration: monitoring with diffusion tensor tractography

We applied diffusion tensor tractography (DTT), a recently developed MRI technique that reveals the microstructures of tissues based on its ability to monitor the random movements of water molecules, to the visualization of peripheral nerves after injury. The rat sciatic nerve was subjected to contusive injury, and the data obtained from diffusion tensor imaging (DTI) were used to determine the tracks of nerve fibers (DTT). The DTT images obtained using the fractional anisotropy (FA) threshold value of 0.4 clearly revealed the recovery process of the contused nerves. Immediately after the injury, fiber tracking from the designated proximal site could not be continued beyond the lesion epicenter, but the intensity improved thereafter, returning to its pre-injury level by 3 weeks later. We compared the FA value, a parameter computed from the DTT data, with the results of histological and functional examinations of the injured nerves, during recovery. The FA values of the peripheral nerves were more strongly correlated with axon-related (axon density and diameter) than with myelin-related (myelin density and thickness) parameters, supporting the theories that axonal membranes play a major role in anisotropic water diffusion and that myelination can modulate the degree of anisotropy. Moreover, restoration of the FA value at the lesion epicenter was strongly correlated with parameters of motor and sensory functional recovery. These correlations of the FA values with both the histological and functional changes demonstrate the potential usefulness of DTT for evaluating clinical events associated with Wallerian degeneration and the regeneration of peripheral nerves.     

联合弥散加权成像与弥散张量成像对缺血性小卒中诊断及预后评估的价值

目的探讨联合应用弥散加权成像（DWD与弥散张量成像（DTI）技术在诊断、评估缺血性小卒中的价值。方法选择41例氯吡格雷用于急性非致残性脑血管事件高危人群的疗效研究课题入组的缺血性小卒中患者。28例患者行MRI基线扫描（发病后3d内）及随访MRI复查,13例仅做基线扫描。其中1例因并发出血终止研究,其余40例患者均在发病后3个月接受临床随访。扫描序列包括常规MRI、DWI及DTI序列。重建表观弥散系数（ADC）图、部分各向异性（FA）图、FA彩色编码图、弥散张量纤维束成像（DTT）图,分别测量患侧及健侧相应部位ADC值、FA值。对预后的评价采用美国国立卫生研究院卒中评分。结果41例缺血性小卒中患者基线扫描DWI与DTI均发现梗死病灶,其中5例为超急性脑梗死,36例为急性脑梗死。41例患者基线DWI序列上患侧呈高信号,ADC值下降,患侧ADC值与健侧比较,差异具有统计学意义（P〈0．01）;36例急性脑梗死患者患侧FA值明显低于健侧（P〈0．01）,而5例超急性脑梗死患者FA值无特异性改变。28例患者复查时所有患侧ADC值较基线进一步升高,FA值下降（尸均〈0．01）。DTT图显示的19例皮质脊髓束受累和6例胼胝体受损患者预后较差,其余患者预后较好。结论DWI技术能早期发现缺血性小卒中病灶、帮助定位诊断,而DTI技术能更好地反映患者白质纤维束情况、指导康复治疗。联合应用两者有助于缺血性小卒中的诊断及预后评估。     

桥脑小脑束扩散张量成像参数预测大脑中动脉脑梗死患者步行能力恢复的临床应用

目的探讨扩散张量成像(DTI)检查脑梗死恢复期患者桥脑小脑束的扩散参数在发病3个月内和1年后的动态改变,分析其与脑卒中后远期步行能力的关系。方法选取亚急性期(病程3周~3个月)大脑中动脉供血区梗死偏瘫患者30例,分别于发病3个月内(首次)和发病1年后(随访时)采用DTI在感兴趣区桥脑小脑束的小脑中脚区域测定左、右两侧的部分各向异性(FA)值作为影像学参数;同时采用国立卫生研究所卒中量表(NIHSS)对入选患者的神经功能缺损情况进行评估,包括上、下肢运动评定部分,并作为偏瘫分级(PG)的依据(即上肢和下肢运动评分之和);并于随访时,采用Brunel平衡量表(BBA)、改良的Rankin量表(mRS)和功能独立性评定量表(FIM)分别评定入选患者的平衡功能、功能预后和生活自理能力。结果首次扫描后发现,桥脑小脑束未受累侧FA值(0.499±0.053)和随访时桥脑小脑束未受累侧的FA值(0.490±0.094)明显低于同期受累侧。首次检测所得桥脑小脑束的rFA值与首次和随访时的下肢运动PG分值、上肢运动PG分值、运动总PG分值和FIM评分呈显著相关,差异均有统计学意义(P<0.05)。随访时,上肢、下肢和总运动结局是否良好与桥脑小脑束的rFA值显著相关,差异均有统计学意义(P<0.05)。首次桥脑小脑束的rFA值预测下肢运动结局的ROC曲线下面积比值为0.84(P=0.002),最佳界值点为0.92(敏感度71.4%,特异度73.9%)。结论亚急性期大脑中动脉梗死患者桥脑小脑束的DTI参数(rFA值)可预测其长期运动能力的恢复情况,且桥脑小脑束的rFA值是预测下肢运动结局是重要参考指标。     

亚急性脑梗塞MR扩散张量的评价

目的　评价MR扩散张量 (DTI)中各向同性成像、表观扩散系数 (ADC)图像、部分各向异性 (FA)图像、各向异性体积比 (VR)图像在诊断亚急性脑梗塞中的作用。方法　随机选取 13个亚急性脑梗塞患者 (共 17个病灶 ) ,利用扩散张量成像 (DTI)、扩散加权成像 (DWI)、T2 加权成像 (T2 WI)FSE序列等技术进行头颅MR扫描 ,并运用原始数据重建出ADC、FA、VR图像。结果　各向同性成像、ADC、FA、VR、DWI、T2 WI均能不同程度地检测出病灶 ,其中各向同性成像技术检测出所有的梗塞病灶 ;而ADC图像由于存在假阴性期 ,所以对部分病灶未能检出。结论　各向同性成像技术能更好的检测出亚急性脑梗塞 ,是各向同性成像、ADC、FA、VR、DWI和T2 WI中最敏感的方法     

应用扩散张量成像技术对急性缺血性卒中机体功能障碍与锥体束损伤程度的相关性研究

目的应用扩散张量成像技术(diffusion tensor imaging,DTI)研究急性缺血性卒中机体功能障碍与锥体束损伤程度的相关性。材料与方法收集急性缺血性脑卒中患者在发病急性期内的常规MRI平扫、扩散加权成像、DTI检查、工作站自动生成各向异性指数(fractional anisotropy,FA)图及ADC图,从中筛选出病变累及单侧基底节区的急性缺血性脑卒中患者16例,分别测量病灶区与大脑对侧相应部位的FA值、ADC值、纤维束数量,并计算出纤维束数量健侧与患侧差值,使用mimics软件对病灶体积进行测量,同时使用美国国立卫生研究院卒中量表(NIH Stroke Scale,NIHSS)、临床医学肌力分级对机体功能障碍程度进行评价。使用统计学方法研究健、患侧纤维束数量、FA值、ADC值的差异;统计出数量差值与病灶体积、NIHSS评分、肌力评分的相关性;统计16例患者出现的所有神经系统阳性表现。通过扩散张量纤维束成像(diffusion tensor tractography,DTT)和3D slicer软件在病变区和健侧对应部位重建,对比观察纤维束的形态变化。结果健、患侧锥体束数量、FA和ADC配对t检验有统计学差异(P<0.05,分别为0.001、0.005、0.001)。纤维束数量差值和病灶体积、肌力分级有显著相关关系(r=0.632,P=0.009;r=-0.554,P=0.026);病灶体积和NIHSS评分有显著正相关关系,差异及相关性有统计学意义(r=0.789,P=0.000)。健、患侧纤维束数量差值和NIHSS评分无相关性(P=0.061),FA值减少程度和ADC减少程度无相关性(P=0.890)。患侧纤维束走形异于健侧,部分患侧纤维束受压、变形、移位、断裂,部分健侧纤维束向患侧延伸。结论急性缺血性脑卒中患者机体功能障碍与锥体束损伤程度有相关性,病灶体积越大,锥体束损伤程度越严重,脑组织损伤程度越重,机体功能障碍程度越明显。     

基于体素的形态学测量分析脑卒中后残障手的机制

目的:采用基于体素的形态学测量(voxel-based morphometry,VBM),分析脑卒中后全脑内华勒变性的状态,揭示残障手的发生机制。方法:23例脑卒中后右侧偏瘫患者分为两组:残障手组11例,非残障手组12例。12例健康人进入健康对照组。采用3.0T核磁共振仪对所有受试者进行弥散张量成像扫描,利用SPM软件进行VBM分析,用双样本t检验对平滑后的参数图分别进行两两组间比较。提取出残障手组和非残障手组之间FA图存在显著差异的脑区,把存在差异的脑区分别应用到所有受试者的FA图上,然后计算每位受试者对应脑区的平均FA值。MD、AD、RD参数图分析与此一致。结果:与非残障手组相比,残障手组病变同侧的脑干、基底核和丘脑、中央前回、额内侧回、辅助运动区、颞上回、顶叶、枕叶和病变对侧的中央后回FA值显著减小;病变同侧基底核和丘脑的MD、AD值显著增加;病变同侧的基底核和丘脑、脑干的RD值显著增加。残障手组FA较小的脑区(或MD、AD、RD较大的脑区)明显比非残障手组的相应脑区范围广。结论:病变同侧脑干、基底核和丘脑、中央前回、额内侧回、辅助运动区、颞上回、顶叶、枕叶和对侧中央后回华勒变性在残障手形成中起重要作用。     

磁共振扩散张量成像对脊髓型颈椎病脊髓慢性损伤的评价

目的 评价磁共振扩散张量成像（DTI）对脊髓型颈椎病脊髓慢性损伤早期诊断的可行性。方法 采用单次激发平面回波成像（SE-EPI）序列对31例临床确诊的脊髓型颈椎病患者行颈髓常规MRI和DTI检查。测量病变处ADC值和FA值并按病变常规T2WI高信号阳性与阴性分组进行数据分析,计算常规MRI和DTI对颈髓病变检出的敏感度、特异度、阳性预测值（PPV）、阴性预测值（NPV）。结果所有脊髓型颈椎病患者均能完成DTI检查,后处理图像颈髓显示清晰,无明显图像变形及伪影。9例（29%）表现为颈髓病变T2WI高信号的患者均出现颈髓受压平面ADC值升高,FA值下降,平均ADC值为（1183.44±121.96）×10-6mm2/s,相应FA值为（432.56±59.97）×10-3,与正常值相比有统计学意义;22例（71%）颈髓病变T2WI高信号阴性患者中,7例（32%）病变处平均ADC值及FA较正常值无明显变化;15例（68%）颈髓受压平面ADC值升高,FA值下降,平均ADC值（1055.07±80.61）×10-6mm2/s,FA值为（501.87±41.09）×10-3,有统计学意义。检查方法的敏感度常规T2WI为29.0%,DTI为67.7%;特异度常规T2WI为71.0%,DTI为22.6%;PPV常规T2WI为27.3%,DTI为72.7%;NPV常规T2WI为75.9%,DTI为24.1%。结论 DTI较常规MRI更早期而准确地诊断脊髓型颈椎病颈髓慢性损伤,是一种显示脊髓型颈椎病颈髓病变和观察病变修复过程的有效手段。     

Prediction of motor outcomes and activities of daily living function using diffusion tensor tractography in acute hemiparetic stroke patients

[Purpose] The efficacy of diffusion tensor imaging in the prediction of motor outcomes and activities of daily living function remains unclear. We evaluated the most appropriate diffusion tensor parameters and methodology to determine whether the region of interest- or tractography-based method was more useful for predicting motor outcomes and activities of daily living function in stroke patients. [Subjects and Methods] Diffusion tensor imaging data within 10 days after stroke onset were collected and analyzed for 25 patients. The corticospinal tract was analyzed. Fractional anisotropy, number of fibers, and apparent diffusion coefficient were used as diffusion tensor parameters. Motor outcomes and activities of daily living function were evaluated on the same day as diffusion tensor imaging and at 1 month post-onset. [Results] The fractional anisotropy value of the affected corticospinal tract significantly correlated with the motor outcome and activities of daily living function within 10 days post-onset and at 1 month post-onset. Tthere were no significant correlations between other diffusion tensor parameters and motor outcomes or activities of daily living function. [Conclusion] The fractional anisotropy value of the affected corticospinal tract obtained using the tractography-based method was useful for predicting motor outcomes and activities of daily living function in stroke patients.Key words: Stroke, Diffusion tensor tractography, Activities of daily living function     

镜像疗法促进脑卒中上肢功能恢复和皮质脊髓束重塑的弥散张量成像研究

目的 探讨镜像治疗对脑卒中偏瘫患者上肢功能恢复和皮质脊髓束重塑的影响。 方法 2017年3月至2019年3月,皮质下脑卒中伴上肢功能障碍患者42例随机分为对照组(n = 21)和观察组(n = 21)。两组均行常规康复,观察组增加镜像疗法。治疗前和治疗12周后,采用Fugl-Meyer评定量表上肢部分(FMA-UE)进行评定;磁共振弥散张量成像(DTI)获取内囊后肢各向异性分数(FA)。 结果 治疗后,两组FMA-UE评分均显著提高(t > 9.560, P < 0.001),观察组评分增加值高于对照组(t > 2.634, P < 0.05)。治疗前,两组病灶侧内囊后肢FA均较对侧显著减小(t > 11.368, P < 0.001);治疗后,观察组病灶侧内囊后肢FA高于治疗前(t = 2.385, P < 0.05),对照组无显著性差异(t = -0.596, P > 0.05),观察组评分增加值高于对照组(t = 2.306, P < 0.05)。 结论 镜像疗法可促进脑卒中患者的上肢运功功能改善和皮质脊髓束重塑。     

锥体束Wallerian变性的MRI诊断

目的探讨MRI在诊断脑损害后锥体束Wallerian变性中的应用。方法对22例脑损害后锥体束Walle-rian变性患者均行MRI检查。常规行快自旋回波序列(FSE)横断位T1WI(TR 2 286ms,TE 19.6ms)、T2WI(TR4 300ms,TE 113ms)和T2Flair序列(TR 8 502ms,TE 133ms)。视野(FOV)24cm,矩阵320×256,激发次数(NEX)1～2,层厚6mm,层间距1mm,层数21层。22例患者均加扫横轴位DWI(b值为1 000s.mm-2),其中10例另加扫3D-TOF-MRA(TR 26ms,TE 6.8ms)检查。结果 22例患者中,12例患者在脑损害≥4周～≤12个月后行常规MRI检查,主要表现为病变同侧的锥体束呈长T1、长T2信号并同侧大脑脚及桥脑体积稍萎缩;2例患者在脑损害<4周行常规MRI检查,主要表现为病变侧锥体束稍长T1、长T2信号;8例患者在脑损害>1年行常规MRI检查,主要表现为原发病灶、大脑脚及桥脑萎缩并T2Flair像呈现散在斑片稍高信号影。结论 MRI可明确显示脑损害后锥体束Wallerian变性,有助于临床医师对患者运动功能康复的治疗。