血氧水平依赖功能磁共振成像在累及运动区脑肿瘤中的应用

目的：功能磁共振成像对脑肿瘤术前评估具有重要意义,探讨血氧水平依赖功能磁共振成像（Bold-fMRI）在累及运动通路脑肿瘤中的应用价值。方法：对16例累及皮层运动区的脑肿瘤患者行fMRI检查,另以10例健康者作为对照,2例患者术后复查,fMRI采用双侧交替进行的大拇指对掌运动作为任务刺激。所有数据进行离线后处理,fMRI图像使用基于MATLAB平台下运行的SPM99软件进行处理,观察运动皮层区激活情况。结果：每个患者的健、患侧主运动区（M1）、辅助运动区（SMA）均激活,其中12例患侧M1区信号低于健侧,3例患侧M1区信号高于健侧,1例健侧与患侧M1区信号无明显差别,11例患侧M1区信号移位,8例患者患侧SMA区及健侧M1区的激活程度较健康人增强;2例患者复查显示患侧M1皮层激活范围较术前变小。结论：应用fMRI能显示肿瘤、皮层运动功能区之间的关系,对邻近脑运动功能区脑肿瘤患者术前评估具有重要意义。     

健侧顶叶皮层参与卒中急性期脑功能重组:fMRI研究

目的利用功能性磁共振成像(fMRI)技术探讨缺血性卒中急性期的脑功能重组特点。资料与方法采用被动单指运动任务,对4例急性皮质下梗死患者和4名正常人进行fMRI研究,比较正常人与卒中患者之问以及每个卒中患者之问fMRI结果的异同。结果正常人被动单指运动激活对侧感觉运动皮层(SMC)、后顶叶皮层(PPC)和双侧辅助运动区(SMA)。卒中患者健手运动fMRI结果基本同正常人;患手运动时,除1例同(健)侧SMC、SMA、前运动皮层(PMC)激活外,4例均呈现出同侧PPC的激活。结论首次应用fMRI技术采用恒定的被动刺激探讨卒中急性期患者运动恢复的神经机制,结果显示了正常人和脑卒中患者之间fMRI结果的显著差异,反映了卒中急性期脑功能的重组情况,也为卒中急性期健侧半球PPC中介运动恢复提供了新的实验依据。     

臂丛损伤健侧C7神经移位术后大脑运动皮质远期功能重组

目的:运用功能磁共振成像方法研究臂丛根性撕脱伤并行健侧C7神经移位术后大脑运动功能的远期变化。方法:8例经临床检查和手术证实一侧全臂丛根性撕脱伤男性患者(健侧C7术后两年以上)以及9名健康男性被试接受磁共振扫描。运动任务为单侧手的抓握运动。结果:健康对照组单侧手运动时所有被试均主要激活对侧初级运动区和辅助运动区而且偏侧化系数均大于0。组分析结果同样显示单侧手运动主要激活对侧大脑半球运动脑区。患者患肢运动激活双侧运动皮质,但偏侧化系数大于0,提示患肢运动主要激活对侧运动皮质(M1和SMA)。5例右侧臂丛损伤患者组分析结果显示患肢运动主要激活对侧运动皮质。3例左侧臂丛损伤患者单个被试偏侧化系数分析及激活图像显示患肢运动主要激活脑区位于对侧运动皮质。结论:健侧C7神经移位术后,大脑会试图利用原躯体运动区对患肢运动进行控制。     

脑梗死患者手运动功能区fMRI研究

目的 对不同时期脑梗死所致偏瘫患者采用主动手运动任务模式进行功能磁共振成像(functional magnetic resonance imaging,fMRI),研究运动功能区损伤及恢复特点,以指导临床康复治疗.资料与方法 脑梗死所致偏瘫患者40例.累及基底节区25例,皮层区15例.其中急性期15例,亚急性期9例,慢性期16例.采用组块设计进行单手拇指与余4指同步对指运动,所有患者均进行健侧和患侧手的主动运动实验.采用SPM 99软件进行预处理和统计分析.结果 (1)急性期梗死灶累及皮层区组,健侧半球初级感觉运动区(SMC)激活强度及范围明显大于患侧半球.皮层区组患侧半球SMC激活强度及范围均小于基底节区组;(2)梗死灶累及基底节区组,健侧与患侧半球SMC激活强度及范围于急性期与慢性期间差异无统计学意义;(3)病例的纵向观察:患肢功能恢复较好的患者,患侧和(或)健侧半球SMC的激活强度和(或)范围有不同程度增强,同时激活脑区增多,均可见小脑半球的激活;患肢功能恢复较差的患者,患侧半球SMC的激活强度及范围逐渐减小直至消失.结论 (1)fMRI能准确地判定脑梗死患者脑功能区的损伤程度及有无重组的脑功能区;(2)皮层区梗死患者运动功能受损较为严重,SMC起关键作用,其受累程度直接影响运动功能损伤的等级及恢复程度;(3)脑梗死偏瘫患者在运动功能康复治疗过程中,病变周围及远隔部位可出现功能和结构变化,提示存在脑功能区重组.     

原发性开角型青光眼V1区皮层功能变化的功能MRI研究

目的 利用fMRI视网膜皮层映射技术研究原发性开角型青光眼(POAG)患者V1区皮层功能变化.方法 选取15例POAG患者及15名正常志愿者,利用视网膜皮层映射分区刺激和圆形黑白翻转棋盘格刺激采集fMRI数据.采用配对样本t检验比较POAG患者患侧眼与健侧眼V1区的fMRI反应、独立样本t检验比较健侧眼与匹配的正常人眼V1区的fMRI反应和激活.POAG患者患侧眼和健侧眼单独刺激时的V1皮层功能差异与视功能差异做线性相关分析.结果 (1)患侧眼接受刺激时V1区fMRI反应较健侧眼弱(t=4.757,P<0.01),患侧眼和健侧眼fMRI反应分别为(1.24±0.72)%、(2.18±0.93)%.患侧眼、健侧眼分别与其年龄、性别、眼侧别相匹配的正常人眼V1区fMRI反应进行比较:患侧眼较正常人眼反应弱(t=-3.011,P<0.01),患侧眼和匹配眼fMRI反应分别为(1.24±0.72)%、(2.01±0.65)%;健侧眼和匹配眼反应差异无统计学意义(t=0.742,P＞0.05),健侧眼和匹配眼分别为(2.18±0.93)%、(1.95±0.75)%.(2)患侧眼与健侧眼单独刺激的V1皮层功能差异与视功能差异存在线性负相关(r=-0.887,P<0.01).(3)患者的健侧眼与其年龄、性别、眼侧别相匹配的正常人眼比较,患者健侧眼V1激活较正常人眼小(t=-3.801,P<0.01),健侧眼和匹配眼V1激活面积指数分别为0.72±0.12、0.85±0.09.结论 青光眼存在皮层功能损害,而且青光眼皮层功能的损害与视觉功能的损害存在相关一致性;基于fMRI视网膜皮层映射分区的定位、定量测量是一种对青光眼视觉皮层功能变化临床随访、评估测量的有用方法,也是活体人青光眼视觉通路跨突触退变研究的潜在有用工具.     

血氧水平依赖功能磁共振成像在脑功能区肿瘤患者的应用

目的:利用血氧水平依赖功能磁共振技术(BOLD-fMRI),评估肿瘤位于或邻近脑皮层运动功能区的良、恶性肿瘤患者的脑皮层运动功能激活区形态和位置变化,比较和分析两者间激活区体积和最大信号强度的差异。方法:收集30例病理学证实肿瘤位于或邻近脑皮层运动功能区的脑肿瘤患者(恶性肿瘤18例,良性肿瘤12例),应用BOLD-fMRI技术,检查时患者双手同时对指运动,获得脑皮层运动功能区的激活图像,应用工作站对原始数据进行后处理,获得功能区激活图,并与解剖图融合,显示良、恶性肿瘤患者的患侧和健侧脑皮层运动激活区形态和位置;应用SPM 5软件计算和分析双侧脑皮层运动激活区的激活体积及最大信号强度,并用统计学方法分析各组间的差异。结果:肿瘤患侧脑皮层运动功能激活区的范围减小、形状变细长、主要向前或外侧移位;恶性肿瘤的脑皮层运动功能激活区的激活体积和最大信号强度明显小于良性肿瘤者(P0.01)。所有肿瘤患侧脑皮层运动功能激活区的激活体积和最大信号强度明显小于健侧(P0.01)。结论:BOLD-fMRI能直观地显示肿瘤患者脑皮层运动功能激活区的形态和位置变化,有助于外科手术方案的制定;良、恶性肿瘤组之间,肿瘤组与健侧组之间的脑皮层运动功能激活区的激活体积和最大信号强度具有显著性差异。     

磁共振弥散张量成像及脑功能成像在涉及运动通路脑肿瘤中的初步联合应用

目的:初步探讨联合磁共振弥散张量成像(DTI)及脑功能成像(Bold-fMRI)在涉及运动通路脑肿瘤的应用价值,观察肿瘤与功能区及邻近锥体束的关系.材料和方法:采用GE3.0TMRI成像系统,对12例临近运动皮质及锥体束的肿瘤(Ⅲ-Ⅳ级胶质瘤5例,II级胶质瘤3例,海绵状血管瘤2例,脑膜瘤2例)进行检查,均行Bold-fMRI及DTI序列,fMRI应用手的对掌运动或足背屈运动作为任务刺激.所有数据进行离线后处理,应用SPM99软件处理fMRI图像,观察运动皮质激活,DTI采用DTV1.5软件进行纤维束的成像.结果:12例肿瘤FA图显示良好,肿瘤区FA值较健侧比较有明显下降(P<0.05).纤维束重建后7例可见锥体束的消蚀破坏,其中5例伴有变形及移位;3例可见锥体束的单纯变形及受压移位;2例锥体束未见破坏及移位;11例肿瘤患侧手或足运动均可见对侧初级运动皮质(M1)的激活(1例因肢体瘫痪而失败),其中7例并有辅助运动区(SMA)及同侧M1的激活.比较fMRI及纤维束重建图发现肿瘤、功能区及白质束三者之间关系可以清楚显示.3例肿瘤DTI及fMRI联合用于外科神经导航系统,成功的指导手术.结论:DTI及Bold-fMRI联合应用可以更好的观察瘤体、功能区及白质纤维三者关系,辅助术前手术方案的制定,指导手术切除.     

利手和非利手随意运动的全脑功能磁共振成像

目的 利用全脑功能磁共振成像(fMRI)技术，探讨参与利手和非利手简单随意运动的关键脑结构。方法 采用Siemens公司Sonata 1．5T磁共振成像系统，对7名健康右利手志愿者的利手或非利手食指按键运动进行了全脑扫描。数据经头动矫正、空间标准化、空间平滑等预处理后，通过互相关分析分别获得利手和非利手运动的脑激活统计参数图。结果 利手运动主要激活对侧初级运动区(MI)、双侧辅助运动区(SMA)、双侧运动二区(MII)和同侧小脑，而非利手运动除以上区域外还激活了对侧前运动区(PMC)，而且SMA和MII的激活体积大于利手运动。结论 全脑fMRI研究表明，随意运动依赖于大脑皮质和小脑等许多脑结构的参与.与利手运动相比，非利手运动更依赖于SMA和PMC等高级运动控制区.     

不同术式神经移位至桡神经疗效观察

目的 比较不同动力神经移位至桡神经不同部位疗效的差异。方法 自1997年至2000年，采用肋间神经或健侧C7神经根移位至不同部位的桡神经术，治疗全臂丛神经损伤36例，平均随访时间42．39个月，用四格表法统计，计算肌力恢复的有效率。结果 本组总有效率为56％（20／36）；在恢复伸肘功能时，以神经移位至桡神经主干组和移位至肱三头肌肌支组的有效率高，分别为5／8、4／4；在恢复伸腕功能时，健侧C7神经根移位至桡神经发出肱三头肌肌支后的沟内段的有效率最高，为75％（9／12）。结论 移位至桡神经主干术和至肱三头肌肌支术的伸肘功能恢复佳；健侧C7神经根移位至桡神经沟内段术的伸腕功能恢复最好；年龄〈30岁和手术间隔时间〈12个月，有利于桡神经功能恢复。     

功能磁共振成像在脑膜瘤患者运动功能区的应用

目的：探讨血氧水平依赖功能磁共振技术(BOLD-fMRI)在脑膜瘤患者运动功能区术前定位的价值。方法收集10例经术后病理证实的靠近运动区的大脑凸面脑膜瘤患者,采用概率独立成分分析(PICA),进行 ICA 分析。术前术后行远期生活质量评估(KPS)生活状态评分来评价患者的状态。结果双侧主要运动皮层及辅助运动皮层均出现运动功能激活簇,其中患侧激活区与对侧激活区相比较为对称的有6例,出现明显推压移位的有4例,患者运动功能激活区均被肿瘤挤压导致功能区向前或向后移位,并且出现拉伸变形。结论 BOLD-fMRI 能够有效对脑肿瘤患者进行术前运动功能区定位,对脑膜瘤患者术前手术计划的制定能够提供帮助。     

观察脑肿瘤致大脑运动功能重组患者运动神经网络变化的功能性连接MRI研究

目的 应用功能性连接MR成像(fcMRI)技术,观察中央沟附近脑肿瘤所致功能重组患者运动神经网络的改变,为理解肿瘤所致运动功能重组的机制提供新的实验依据.方法 采用1.5 T MR成像系统,对6名正常志愿者及14例功能MRI(fMRI)显示运动功能重组的中央沟附近脑肿瘤患者行fcMRI.分别得到以正常受试者左和右主运动(M1)区、脑肿瘤患者肿瘤侧半球和非肿瘤侧半球M1区为种子体素(兴趣区)的功能连接图.对与以上种子体素呈明显相关的功能连接区的位置、范围、体积进行评估.将所测数据进行t检验和单向方差分析.结果 fcMRI显示6名正常志愿者单侧M1区的功能连接脑区遍布于双侧大脑半球,包括双侧M1区、双侧辅助运动区(SMA)、双侧运动前区(PMC区)等与运动相关的皮层,左右对称分布.左M1区的功能连接区[(9514.17±186.92)mm3]与右M1区者[(9364.67±382.75)mm3]范围基本一致,二者在体积上差异无统计学意义(P>0.05);肿瘤组fcMRI显示:(1)与肿瘤侧M1区所连接脑区的体积[(11193.14±811.29)mm3]明显大于非肿瘤侧M1区的功能连接区[(6549.86±400.94)mm3](P<0.01).肿瘤组肿瘤侧M1区所连接的脑区与正常对照组单侧M1区的功能连接脑区差异有统计学意义(P<0.01),前者明显扩大(P<0.01),提示肿瘤侧M1区与其他运动相关脑区的功能连接增强.其连接脑区的范围与受累手对指运动时同层面fMRI显示的运动功能重组区范围基本一致.(2)肿瘤组非肿瘤侧M1区的功能连接区的体积与正常组比较,差异有统计学意义(P<0.01),前者有减少的趋势(P<0.01),特别是肿瘤侧半球内,提示非肿瘤侧M1区与对侧半球的功能连接破坏.结论 肿瘤组患者肿瘤侧M1区功能连接区的增多提示运动功能重组可能与运动功能传导路径重组或潜在运动路径补偿性开放有关.fcMRI是一种显示颅内肿瘤所致运动神经网络变化的有效手段.     

The effect of prior surgery on blood oxygen level-dependent functional MR imaging in the preoperative assessment of brain tumors

BACKGROUND AND PURPOSE: Blood oxygen level-dependent functional MR imaging (BOLD fMRI) is a clinically useful technique for preoperative mapping of eloquent cortices in patients with brain tumors. The purpose of this study was to determine the effect on BOLD fMRI accuracy of susceptibility artifacts caused by prior surgery by comparing volumes of activation in the primary motor cortex (PMC) of patients with and without prior brain surgery. METHODS: The volumes of fMRI activation of the PMC were measured for the tumor and nontumor sides in patients with (n = 13) and without (n = 30) prior neurosurgery. Statistical comparisons of the volumes were performed by using paired t tests and linear regression analysis. The location and degree of susceptibility artifact were subjectively assessed. RESULTS: No significant difference was found between the mean tumor and nontumor volumes of fMRI activations in patients without prior surgery (P = .51). In patients who had prior surgery, the volume of activation was significantly smaller on the side of the prior operation when compared with the contralateral side (P = .001). The volume of activation on the side of the tumor was also significantly smaller in the patients with prior surgery compared with those without prior surgery (P < .001). Nevertheless, the PMC was identified in all cases, and its location was confirmed intraoperatively. CONCLUSION: Prior surgery is associated with a decrease in the volume of fMRI activation in patients with prior surgery; however, by examining the T2 images, an astute radiologist can recognize this phenomenon, draw the appropriate conclusions, and correctly identify the PMC.     

Functional MRI activation of somatosensory and motor cortices in a hand-grafted patient with early clinical sensorimotor recovery

The aim of this study was to investigate somatosensory and motor cortical activity with functional MRI (fMRI) in a hand-grafted patient with early clinical recovery. The patient had motor fMRI examinations before transplantation, and motor and passive tactile stimulations after surgery. His normal hand and a normal group were studied for comparison. A patient with complete brachial plexus palsy was studied to assess the lack of a fMRI signal in somatosensory areas in the case of total axonal disconnection. Stimulating the grafted hand revealed significant activation in the contralateral somatosensory cortical areas in all fMRI examinations. The activation was seen as early as 10 days after surgery; this effect cannot be explained by the known physiological mechanisms of nerve regeneration. Although an imagination effect cannot be excluded, the objective clinical recovery of sensory function led us to formulate the hypothesis that a connection to the somatosensory cortex was rapidly established. Additional cases and fundamental studies are needed to assess this hypothesis, but several observations were compatible with this explanation. Before surgery, imaginary motion of the amputated hand produced less intense responses than executed movements of the intact hand, whereas the normal activation pattern for right-handed subjects was found after surgery, in agreement with the good clinical motor recovery.     

Plasticity of the human motor cortex in patients with arteriovenous malformations: a functional MR imaging study

BACKGROUND AND PURPOSE: The capacity of the human brain to recover from damage has been explained on the basis of plasticity, according to which remaining areas assume functions that would normally have been performed by the damaged brain. Patients with cerebral arteriovenous malformations (AVMs) involving primary motor areas may present without significant neurologic deficits. We used functional MR imaging to investigate the organization of cortical motor areas in patients with AVMs. METHODS: Cortical motor hand and foot representations were mapped in nine right-handed patients harboring AVMs occupying the hand (n = 6) or foot (n = 3) region of the primary motor cortex (M1). None of the patients exhibited motor deficits. Simple movements of the hand and foot were performed. In eight patients, both right and left extremities were tested; in one patient, only the hand contralateral to the AVM was examined. Localization of activation in the affected hemisphere was compared with that in the unaffected hemisphere and evaluated with respect to the normal M1 somatotopic organization shown in earlier functional MR imaging investigations. RESULTS: Cortical activation showed three patterns: 1) functional displacement within the affected M1 independent of the structural distortion induced by the AVM (n = 4), 2) presence of activation within the unaffected M1 ipsilateral to the moving extremity without activation in the affected M1 (n = 3), and 3) prominent activation in nonprimary motor areas without activation in either the affected or unaffected M1 (n = 2). CONCLUSION: Preliminary evidence suggests that brain AVMs lead to reorganization within the somatotopic representation in M1 and to occasional abnormal expansion into nonprimary motor areas.     

Restored activation of primary motor area from motor reorganization and improved motor function after brain tumor resection

BACKGROUND AND PURPOSE: Reorganization of brain function may result in preservation of motor function in patients with brain tumors. The goal of the present study was to investigate whether function of the primary motor area (M1) was restored and whether motor function improved after brain tumor resection. METHODS: Five patients with metastatic brain tumors located within or near M1 underwent awake surgery with intraoperative cortical mapping and continuous task monitoring. Preoperative and postoperative functional MR imaging (fMRI) was performed during hand clenching, and diffusion tensor imaging (DTI) was performed in 1 case to further characterize the area activated in fMRI. RESULTS: Preoperative fMRI performed during hand clenching demonstrated reorganization of motor function. In patients with severe paresis (cases 3, 4, and 5), clenching of the affected hand induced a large blood oxygen level-dependent response in the right hemisphere, mainly in the anterior temporal lobe, despite the location site of the tumor. Postoperative fMRI during hand clenching demonstrated activation of the contralateral M1. Furthermore, in case 5, DTI detected tracts, possibly the inferior longitudinal fasciculus, arising from anterior temporal activated area as well as tracts connecting the premotor and M1 activated area. This patient demonstrated mirror movement of the hand during the course of motor function recovery. CONCLUSIONS: Tumor resection resulted in restoration of M1 function and improved motor function in patients with preoperative reorganization of M1 function. Furthermore, the preoperative reorganization of motor function in cases with severe paresis may be related to changes in the right hemisphere, including the temporal lobe.     

HIV相关脑痴呆BOLD fMRI运动功能成像

目的:应用功能磁共振成像(fMRI)研究正常健康受试者及HIV相关脑痴呆患者的右手运动功能区并且探讨其应用价值.方法:10例HIV相关脑痴呆患者和8例健康受试者,设计右手相关运动功能实验,采取右手抓握运动方法,结合患者情况分析早期认知运动功能损伤的皮质位置区域和激活情况.结果:正常健康受试者右手运动功能区多位于左侧(对...     

运动相关大脑皮层的功能磁共振成像

目的 :应用功能磁共振成像技术对运动皮层在运动准备及执行阶段的功能活动分布进行研究。方法 :应用事件相关功能磁共振成像技术 ,记录 14名右利手健康受试者在序列手指运动过程中大脑皮层的功能活动 ,获得运动准备和运动执行阶段的脑激活图。结果 :双侧辅助运动区前部、双侧运动前区后部及双侧后顶叶前部在运动准备与执行过程均有激活。结论 :研究表明运动皮层存在于运动准备和执行阶段均有激活的脑功能区 ,事件相关功能磁共振成像技术可应用于脑活动机制的研究。