早期MRI检查对颅内病变术后评估的临床应用

影响脑胶质瘤等颅内病变预后的因素很多 ,除年龄 ,身体状况 ,肿瘤恶性程度外 ,手术切除程度也被认为是一个重要的指标[1] ,而对切除程度的评价 ,首先是对残余肿瘤的准确判断。以往常凭手术者根据术中情况及经验判断 ,缺乏有效依据。本文对 32例颅脑病变术后病例进行多个时期ＭＲＩ检查 ,以排除影响判定结果的因素 ,确立ＭＲＩ检查的最佳时期。资料和方法1.一般资料 :男 12例 ,女 2 0例 ,年龄 18～69岁 ,平均 4 9 8岁。颅内疾病 :脑胶质瘤 8例 ,脑膜瘤 13例 ,脑内血肿 11例。2 .方法 :将资料分成肿瘤与非肿瘤两组 ,肿瘤组又根据是否具有包膜 …     

脑静脉窦血栓形成的影像学表现及脑实质病变预测

目的总结脑静脉窦血栓形成(CVST)患者的临床和MRI表现特征并探讨继发脑实质病变的预测因素。方法回顾57例CVST患者的临床及头颅MRI资料,分析患者MRI表现特征,并对临床及影像学指标进行对比分析。结果57例患者中男22例,女35例,年龄15~72岁(平均35岁)。临床症状头痛29例,癫痫发作11例,感觉变化8例,局灶性神经功能缺损9例;头颅MRI示静脉窦血栓形成部位上矢状窦9例,横窦2例,乙状窦1例,直窦1例,其中同时累及2个或2个以上静脉窦44例。静脉窦血栓伴发脑实质病变36例,其中出血性静脉梗死20例,非出血性静脉梗死12例,脑实质内出血4例。对伴和不伴脑实质病变2组患者的对比分析显示,伴脑实质病变组女性比例明显高于不伴脑实质病变组;伴脑实质病变组癫痫、感觉异常及局部神经功能缺损症状发生率均明显高于不伴脑实质病变组;伴脑实质病变组直窦血栓的发生率明显高于不伴脑实质病变组(P<0.05)。结论MRI可清楚显示CVST的直接及间接征象,通过分析CVST患者的临床和静脉窦血栓表现特征还可帮助预测严重的脑实质病变发生风险。     

功能性磁共振辅助神经导航手术治疗运动功能区病变

目的 研究功能性磁共振成像(fMRI)辅助神经外科导航系统在运动功能区病变手术中的应用价值。方法 利用血氧水平依赖性测量(BOLD)成像技术，对14例运动功能区病变病人(胶质瘤11例，脑膜瘤2例，转移癌1例)行fMRI检查，将有关数据及图像进行相关分析处理，得到活化功能区图像，将功能像与结构像融合，输入神经外科导航系统，术中进行功能区定位，指导手术。结果病人术中病灶影像均获得等体积全切除，术后神经功能障碍未加重。结论 fMRI检查可以为功能区病变术前手术计划的制定提供有价值的信息，结合导航系统，可在术中精确定位功能区，避免损伤，降低致残率。     

3D ASL显示手运动功能区与附近病变关系的研究

目的基于脑功能磁共振成像(fMRI)与术中皮层直接电刺激(direct current stimulation,DCS技术,探索三维动脉自旋标记(3D-arterial spin labeling,3D-ASL)评估脑部疾病患者脑皮层手运动功能区与附近病变关系的价值。方法给46例大脑皮层手运动功能区附近病变患者行ASL的运动态与静息态fMRI扫描,计算得到能够显示手运动功能区与附近病变关系的图像,并与术中DCS及fMRI结果相比较;评估3D ASL显示手运动功能区与附近病变关系的准确性。结果本组46例患者的3D ASL减影图像上手运动功能区均能显示,表现为手运动功能区受累、分散、变小、信号强度降低、变形、移位或无改变等;并且与DCS和fMRI结果一致。结论 3D ASL显示的脑部疾病患者脑皮层手运动功能区与附近病变关系与DCS和fMRI的结果一致,有很好的临床应用价值。     

累及脑皮质运动功能区的动静脉畸形术前磁共振功能定位成像

目的探讨术前采用功能磁共振（fMRI）定位在累及皮质运动功能区的动静脉畸形病人治疗中的作用。方法对19例动静脉畸形累及皮质运动区的病人,采用fMRI观察对指运动时受累皮质运动区的激活情况,分析病灶与激活区的关系。结果本组病例在fMRI检查中均能显示运动区的激活情况。18例表现为激活区与病灶分界清晰,1例表现为两者分界欠清。结论术前fMRI检查可良好显示动静脉畸形与其所在的皮质功能区的关系,对于手术切除具有重要的参考价值。     

立体定向引导显微手术切除脑功能区病变

目的探讨立体定向引导显微手术治疗脑功能区病变的临床效果和应用价值。方法应用立体定向仪和手术计划系统,对8例脑功能区病灶进行立体定向开颅显微手术切除。结果 8例病灶均定位准确,显微镜下全切。6例术前有癫痫的患者术后4例发作完全消失,另2例明显减轻。2例胶质瘤病人1例术后13月复发。2例转移瘤病人1例死于原发病,1例颅内再次转移。2例术前无神经功能障碍者术后出现对侧肢体无力,经治疗1例恢复,1例改善。3例合并神经功能障碍者术后均获得不同程度的改善。结论立体定向引导显微手术治疗脑功能区病变定位准确,侵袭性小,有助于提高病变全切率及降低手术并发症。     

脑膜病变致脑膜强化的MRI表现及其临床意义

目的　研究脑膜病变致脑膜强化的磁共振成像（ＭＲＩ）表现及其与临床的关系。方法　对４３ 例ＭＲＩ增强扫描表现为脑膜强化的患者进行分析。结果　ＭＲＩ脑膜强化见硬膜型强化３１例,软膜型强化１２例;其中化脓性脑膜炎１４ 例,结核性脑膜炎、脑梗死各７ 例,病毒性脑膜炎、脑膜癌病、血管畸形各５ 例,与临床诊断一致;ＭＲＩ平扫所见正常１２ 例,局部脑膜增厚１１ 例,脑内病灶２０ 例。结论　脑膜强化的类型与病因有一定关系,ＭＲＩ增强扫描有助于发现脑膜病变。     

磁共振成像对伽玛刀治疗颅内病变的疗效评价

近年来 ,由于伽玛刀治疗脑部疾病广泛应用 ,从1996年～ 2 0 0 1年 10月 ,我院使用伽玛刀治疗脑肿瘤及脑血管畸形病例共三千余例 ,其中经磁共振追踪观察病例 180 0例 ,现将结果报告如下。资料与方法1.一般资料　男性 115 3例 ,女性 6 4 7例。年龄3～ 79岁 ,平均 35 .8岁。其中脑血管畸形 312例(17.3%) ,脑肿瘤 1488例 (86 .7%)。所有病例均经CT、MRI或DSA造影检查。其中 2 82例为手术后复发或残留的肿瘤病人 ,占 2 3.87%。我们在术后 6～ 12个月直到 36个月 ,不定期用MRI随访 ,磁共振疗效判定标准 ,脑动静脉畸形及海绵状血管瘤用闭塞率…     

胼胝体病变的临床与CT、MRI表现

目的：分析胼胝体病变临床表现及CT、MRI影像学特征。材料与方法：搜集经CT、MRI检查后发现胼胝体病变37例（其中15例经手术及定向穿刺后病理证实）。结果与结论：37例胼胝体病变包括所胼胝体发育不全6例、脂肪瘤5例，外伤及脑血管意外致血肿11例、肿瘤13例（胶质母细胞瘤3例、Ⅰ～Ⅱ级星形细胞瘤5例、淋巴瘤3例、转移后2例）、血管畸形及多发性硬化各1例。除8例脑外伤以外，其他病人临床上均有长期头晕、头痛、突发意识障碍、癫痫等表现、但非特征性改变。CT、MRI对胼胝体病变（无论是原发或是继发）的发现、诊断及鉴别诊断均有重要的价值，MRI在定位上较CT更为精确．从而为术前手术方式的选择，术后放疗的定位准确提供更多有用信息。     

脑小血管病变与临床诊治

随着对脑血管病临床研究的不断深入和核磁共振成像各项检测功能的开发和利用,脑小血管病变（SVD）正日益受到人们的关注。由于SVD是隐匿性渐进发展的,所以以往人们对它往往认识不足。血管性认知损害和痴呆与SVD有着密切的关系,SVD的后期可对患者造成不可逆性损害。本文就SVD的病理生理变化、相关危险因素以及临床治疗中的一些注意事项作一综述。     

Blunted activation in orbitofrontal cortex during mania: a functional magnetic resonance imaging study.

BACKGROUND: Patients with bipolar disorder have been reported to have abnormal cortical function during mania. In this study, we sought to investigate neural activity in the frontal lobe during mania, using functional magnetic resonance imaging (fMRI). Specifically, we sought to evaluate activation in the lateral orbitofrontal cortex, a brain region that is normally activated during activities that require response inhibition. METHODS: Eleven manic subjects and 13 control subjects underwent fMRI while performing the Go-NoGo task, a neuropsychological paradigm known to activate the orbitofrontal cortex in normal subjects. Patterns of whole-brain activation during fMRI scanning were determined with statistical parametric mapping. Contrasts were made for each subject for the NoGo minus Go conditions. Contrasts were used in a second-level analysis with subject as a random factor. RESULTS: Functional MRI data revealed robust activation of the right orbitofrontal cortex (Brodmann's area [BA] 47) in control subjects but not in manic subjects. Random-effects analyses demonstrated significantly less magnitude in signal intensity in the right lateral orbitofrontal cortex (BA 47), right hippocampus, and left cingulate (BA 24) in manic compared with control subjects. CONCLUSIONS: Mania is associated with a significant attenuation of task-related activation of right lateral orbitofrontal function. This lack of activation of a brain region that is usually involved in suppression of responses might account for some of the disinhibition seen in mania. In addition, hippocampal and cingulate activation seem to be decreased. The relationship between this reduced function and the symptoms of mania remain to be further explored.     

Neuronal injury in the motor cortex after chronic stroke and lower limb motor impairment: a voxelbased lesion symptom mapping study

Many studies have examined motor impairments using voxel-based lesion symptom mapping, but few are reported regarding the corresponding relationship between cerebral cortex injury and lower limb motor impairment analyzed using this technique. This study correlated neuro- nal injury in the cerebral cortex of 16 patients with chronic stroke based on a voxel-based lesion symptom mapping analysis. Neuronal injury in the corona radiata, caudate nucleus and putamen of patients with chronic stroke could predict walking speed. The behavioral measure scores were consistent with motor deficits expected after damage to the cortical motor system due to stroke. These findings suggest that voxel-based lesion symptom mapping may provide a more accurate prognosis of motor recovery from chronic stroke according to neuronal injury in cerebral motor cortex.     

影像学引导的立体定向脑活检手术

目的探讨现代神经成像技术(CT、MRI)引导的立体定向脑病变活检术对组织病理学诊断的可靠性和正确性,总结手术操作方法和技术要点。方法采用CT、MRI与立体定向技术相结合,进行脑部病变的活检手术共605例,其中450例用CT或MRI片目测靶点坐标定位,155例采用计算机辅助的立体定向手术(CAPN)工作站,自动计算靶点和规划活检入路。结果522例确诊为各种脑肿瘤,39例为炎性病理,23例为寄生虫或先天性囊肿,16例未能提供可供确诊的病理,阳性诊断率为97.36%。并发症15例,其中2例死亡。结论先进影像技术引导下的立体定向脑病变活检术是神经内、外科脑部病变获得定性诊断安全、可靠的手术方法。术中应注意改进操作方法,以提高病理诊断的阳性率,并达到微侵袭性手术的要求。     

Relation of bimanual coordination to activation in the sensorimotor cortex and supplementary motor area: analysis using functional magnetic resonance imaging

The aim of this study was to analyze how functional activation in the supplementary motor area (SMA) and sensorimotor cortex (SMC) is related to bimanual coordination using functional magnetic resonance imaging. Subjects included 24 healthy volunteers, 15 of whom were right-handed and 9 left-handed. Three kinds of activation tasks, all of which required the repetitive closing and opening of a fist, were performed: unimanual movement of the nonpreferred hand (task A); simultaneous, agonistic movement of both hands (task B); simultaneous, antagonistic movement of both hands (task C). The SMA activation during task C was more pronounced than that during the other two tasks for right and left handers. The results suggested that the activation of the SMA, at least during a simple motion used in the present study, was little influenced by whether the motion was unimanual or bimanual but instead how the bimanual motion was composed of the motion element of a single hand. The SMC activation during task C was significantly larger than that during task B, whereas hemispheric differences in the activation were not found. This indicated that the complexity of the bimanual movement also affected the SMC activation.     

The involvement of primary motor cortex in mental rotation revealed by transcranial magnetic stimulation

We used single‐pulse transcranial magnetic stimulation of the left primary hand motor cortex and motor evoked potentials of the contralateral right abductor pollicis brevis to probe motor cortex excitability during a standard mental rotation task. Based on previous findings we tested the following hypotheses. (i) Is the hand motor cortex activated more strongly during mental rotation than during reading aloud or reading silently? The latter tasks have been shown to increase motor cortex excitability substantially in recent studies. (ii) Is the recruitment of the motor cortex for mental rotation specific for the judgement of rotated but not for nonrotated Shepard & Metzler figures? Surprisingly, motor cortex activation was higher during mental rotation than during verbal tasks. Moreover, we found strong motor cortex excitability during the mental rotation task but significantly weaker excitability during judgements of nonrotated figures. Hence, this study shows that the primary hand motor area is generally involved in mental rotation processes. These findings are discussed in the context of current theories of mental rotation, and a likely mechanism for the global excitability increase in the primary motor cortex during mental rotation is proposed.     

Plasticity of the human motor system following muscle reconstruction: a magnetic stimulation and functional magnetic resonance imaging study

OBJECTIVE: Although motor system plasticity in response to neuromuscular injury has been documented, few studies have examined recovered and functioning muscles in the human. We examined brain changes in a group of patients who had a muscle transfer. METHODS: Transcranial magnetic stimulation (TMS) was used to study a unique group of 9 patients who had upper extremity motor function restored using microneurovascular transfer of the gracilis muscle. The findings from the reconstructed muscle were compared to the homologous muscle of the intact arm. One patient was also studied with functional magnetic resonance imaging (fMRI). RESULTS: TMS showed that the motor threshold and short interval intracortical inhibition was reduced on the transplanted side while at rest but not during muscle activation. The difference in motor threshold decreased with the time since surgery. TMS mapping showed no significant difference in the location and size of the representation of the reconstructed muscle in the motor cortex compared to the intact side. In one patient with reconstructed biceps muscle innervated by the intercostal nerves, both TMS mapping and fMRI showed that the upper limb area rather than the trunk area of the motor cortex controlled the reconstructed muscle. CONCLUSIONS: Plasticity occurs in cortical areas projecting to functionally relevant muscles. Changes in the neuronal level are not necessarily accompanied by changes in motor representation. Brain reorganization may involve multiple processes mediated by different mechanisms and continues to evolve long after the initial injury. SIGNIFICANCE: Central nervous system plasticity following neuromuscular injury may have functional relevance.     

静息态脑功能成像与皮层电刺激定位皮质运动区的对照研究

目的 以术中皮层电刺激为对照,评价运动区附近脑肿瘤患者术前运用基于血氧水平依赖(BOLD)的静息态功能磁共振成像(rs-fMRI)方法定位皮质运动区的准确性.方法 选取18例运动区脑肿瘤患者,手术前采用rs-fMRI定位皮质运动区,以术中皮层电刺激作为皮质运动区定位的标准技术,比较两种技术的符合度,以评价rs-fMRI定位皮质运动区的准确性.结果 rs-fMRI与术中皮层电刺激的吻合率为92.9％,肿瘤全切率为77.8％,11例术后肌力不变,4例术后肌力好转,3例术后肌力下降.结论 rs-fMRI具有较高的敏感性和精确度,可作为术前皮质运动区定位的新方法,为手术方案的制定及预后评估提供有价值的信息.     

Multi-modality mapping of motor cortex: comparing echoplanar BOLD fMRI and transcranial magnetic stimulation

Summary Multiple non-invasive methods of imaging brain function are now available for presurgical planning and neurobiological research. As these new methods become available, it is important to understand their relative advantages and liabilities, as well as how the information gained compares across different methods. A current and future trend in neurobiological studies as well as presurgical planning is to combine information from different imaging techniques. Multi-modal integration may perhaps give more powerful information than each modality alone, especially when one of the methods is transcranial magnetic stimulation (TMS), with its ability to non-invasively activate the brain. As an initial venture in cross comparing new imaging methods, we performed the following 2 studies, locating motor cortex with echoplanar BOLD fMRI and TMS. The two methods can be readily integrated, with concurring results, although each have important limitations.     

Ipsilateral involvement of primary motor cortex during motor imagery

To investigate whether motor imagery involves ipsilateral cortical regions, we studied haemodynamic changes in portions of the motor cortex of 14 right-handed volunteers during actual motor performance (MP) and kinesthetic motor imagery (MI) of simple sequences of unilateral left or right finger movements, using functional magnetic resonance imaging (fMRI). Increases in mean normalized fMRI signal intensities over values obtained during the control (visual imagery) task were found during both MP and MI in the posterior part of the precentral gyrus and supplementary motor area, both on the contralateral and ipsilateral hemispheres. In the left lateral premotor cortex, fMRI signals were increased during imagery of either left or right finger movements. Ipsilateral cortical clusters displaying fMRI signal changes during both MP and MI were identified by correlation analyses in 10 out of 14 subjects; their extent was larger in the left hemisphere. A larger cortical population involved during both contralateral MP and MI was found in all subjects. The overall spatial extent of both the contralateral and the ipsilateral MP + MI clusters was approximately 90% of the whole cortical volume activated during MP. These results suggest that overlapping neural networks in motor and premotor cortex of the contralateral and ipsilateral hemispheres are involved during imagery and execution of simple motor tasks.