Objective:To investigate the feasibility of tractography of the cervical spinal cord by SE-EPI sequence to show fibers of normal volunteers and patients with some diseases of the cervical spinal cord.Methods:22 normal volunteers,6 patients with syringomyelia and 3 patients with spinal cord tumors received DTI examination by SE-EPI sequence.Get the tractography by using fiber tracking software.Results:Tractography of the white matter of normal volunteers were obtained and were accordance to the anatomy of the cervical spinal cord.Tractography of syringomyelia patients demonstrated hollow of the cord.Tumors could also be delineated macroscopically.Conclusion:Tractography of the cervical spinal cord applies macroscopic information and is helpful to surgery and treatment of disorders.

Objective: To analyze normal diffusion tensor imaging (DTI) parameters of the cervical spinal cord quantitatively in healthy volunteers. Methods: Twenty two volunteers underwent DTI examination. ADC, FA and RA maps were generated. On sagittal views, the ROIs were placed in different levels of the cervical spinal cord (C1-C7), while on axial views, ROIs were placed in the anterior, posterior funiculus and bilateral lateral corticospinal tracts (LCTs) at C3 level. ADC, FA, RA and eigenvalues of ROIs were measured. Results: On sagittal views, FA and RA values at the level of Co were significantly higher than those of others (P<0.05). On axial views, FA and RA values in the anterior region were significantly lower than others, while ADC values were significantly higher than others (P<0.05). Conclusion: DTI using SE-EPI sequence can clearly show the imaging of cervical spinal cord in healthy volunteers. Cervical spinal cord can be quantitatively analyzed with DTI.

INTRODUCTION:Motor neuron damage and cortical spinal tract (CST) degeneration in amyotrophic lateral sclerosis (ALS) are difficult to visualise and quantify on conventional magnetic resonance imaging (MRI).CLINICAL PICTURE:We studied 8 ALS patients and 12 normal volunteers using diffusion tensor imaging (DTI) and fibre tractography using fibre assignment by continuous tracking (FACT) to study the fibres of the CST and the posterior thalamic radiation (PTR), a nonmotor tract.OUTCOME:Fibre tractography was successfully performed in all normal volunteers and all patients except 1. The fibre bundles of the CST, but not the PTR, were significantly reduced (P <0.05) in patients compared to normal volunteers.CONCLUSION:Fibre tractography can visualise axonal degeneration in the CST and may provide supplementary information about upper motor neuron disease in ALS patients.

Objective To study the changes of motor cortex in patients with amyotrophic lateral sclerosis(ALS)while executing sequential finger tapping movement by using blood oxygenation level dependent(BOLD)functional MRI.Methods Fifteen patients with definite or probable ALS and 15 age and gender matched normal controls were enrolled in the BOLD study,and all the subjects were right-handed with no other diseases or any recent medication history.A 3.0 T MR scanner was employed and gradient echo EPI(GRE-EPI)sequence was used to acquire the functional images.Subjects executed sequential finger tapping movement at a frequency of 1-2 Hz during a block design task.fMRI data were analyzed by using statistical parametric mapping(SPM)2.Volume of activated brain areas was compared with the use of a Student's t-test.Results Bilateral primary sensorimotor cortex(PSM),bilateral posterior aspect of premotor area(PA),bilateral supplementary motor area(SMA),contralateral inferior lateral premotor area (ILPA),bilateral parietal region(PAR),and ipsilateral cerebellum showed activation in both ALS patients and normal controls when executing the same motor task.The activation areas in bilateral PSM and bilateral posterior aspect of PA(right hand ipsilateral activation:ALS(924.5±141.1)mm3,control(829.9±98.4)mm3,P=0.05;right hand contralateral activation:ALS(9143.8±702.8)mm3,control(8638.8±506.4)mm3,P＜0.05;left hand ipsilateral activation:ALS(1162.5±357.4)mm3,control(902.5±184.2)mm3,P＜0.05;left hand contralateral activation:ALS(8255.2±870.2)mm3,control (5934.6±616.4)mm3,P＜0.05),bilateral SMA(right hand bilateral activation:ALS(6564.3±720.6)mm3,control(4710.7±416.3)mm3,P＜0.05;left hand bilateral activation:ALS(6970.5±961.8)mm3,control(3688.9±672.3)mm3,P＜0.05),and ipsilateral cerebellum(right hand ipsilateral activation:ALS(2720.0±1154.2)mm3,control(254.3±84.4)mm3,P＜0.05;left hand ipsilateral activation:ALS(4794.4±1237.0)mm3,control(1689.0±719.6)mm3,P＜0.05)were significantly larger in ALS patients than in normal controls.Extra activation areas including ipsilateral ILPA,contralateral cerebellum and bilateral posterior limb of internal capsule were only detected in ALS patients.Conclusions Similar activation areas were seen in both groups while executing the same motor task,but the activated areas were more prominent in ALS group.The increased activation areas in ALS patients may represent neural reorganization.while the extra activation areas in ALS patients may indicate functional compensation.

Objective To study the signal changes and metabolic alterations in the basal ganglia (BG)by using magnetic resonance imaging(MRI)and proton magnetic resonance spectroscopy(MRS)in patients with hepatic encephalopathy with and without parkinsonism.Methods MRI and MRS in the basal ganglia were performed in 27 patients(22 males,5 females,age ranging from 29 to 62 years)with liver cirrhosis and hepatic encephalopathy.14 of the 27 patients were classified as having parkinsonian signs evaluated by Unified Parkinson's Disease Rating Scale(UPDRS)test.18 age-matched healthy volunteers (13 males,5 females,age ranging from 24 to 51 years)underwent MRI and MRS as a control group. Results NAA/Cr levels(average numbers are 1.40±0.03,1.35±0.03 respectively)showed no statistical difference between cirrhotic patients with hepatic encephalopathy and the control group(t=1.16,t=0.87, P0.05).Values of signal hyperintensities(average numbers are 1.03±0.002,1.04± 0.003 respectively)in globus pallidus and ratios of mI/Cr(average numbers are 0.63±0.01,0.61± 0.02 respectively)and Cho/Cr(average numbers are 0.82±0.03,0.80±0.02 respectively)showed no statistically significant differences between the control group and the 13 patients without parkinsonism(t= 0.63,t=-0.52,t=-0.54,P0.05),whereas values of signal hyperintensities(average numbers are 1.18±0.001,1.04±0.003 respectively)in globus pallidus and ratios of mI/Cr(average numbers are 0.39±0.02,0.63±0.01 respectively)and Cho/Cr(average numbers are 0.68±0.01, 0.82±0.03 respectively)shows statistically significant difference in patients without and with parkinsonism (t=-5.16,t=7.61,t=4.12,P0.05).In patients with cirrhosis,the values of signal hyperintensities in globus pallidus were inversely correlated with the ratio for mI/Cr(r=-0.764,P0.05)and Cho/Cr (r=-0.553,P0.05),respectively.Conclusion MRI and MRS may be useful tools in the evaluation of extrapyramidal impairment of patients with hepatic encephalopathy.

Objective: To detect neuronal network activity of specific brain areas in craving state induced by heroin related cues. Methods: Ten right-handed heroin male patients and 10 healthy men were recruited in the case-control study. They were performed the whole brain scan with 1.5T MR scanner when presented with natural scenery and heroin related cues. The differences of brain areas activation were analyzed when two group subjects watched heroin related cues and heroin patients watched natural scene and heroin related cues, respectively. Data analysis were applied with Analysis of Functional NeuroImaging (AFNI) soft package. Results: (1) Brain activation in left prefrontal cortex was more obvious in heroin patients compared with healthy controls while presented with heroin related cues. (2) When heroin patients watched heroin related cues and natural scenery, there were significant activated brain areas located mainly in the left anterior cingulated cortex, BA10, culmen of cerebellum, periaqueductal gray (PAG), and right precuneus. Conclusion: The activation of specific brain areas in craving state induced by heroin related cues were located in the left anterior cingulated cortex and left prefrontal cortex. PAG may be involved in the formation and sustain of craving.

Objective To detect the patholgical changes of amyotrophic lateral sclerosis (ALS) with magnetic resonance spectrum imaging (MRSI), diffusion tensor imaging (DTI) and magnetic resonance imaging (MRI), to compare their differences and values in the diagnosis of ALS. Methods Twelve ALS patients were compared to 12 normal controls. Fractional anisotropy (FA) and mean diffusivity (MD) were measured at various locations in the corticospinal tract (CST), including the subcortical white matter (SWM), centrum semiovale (CS), periventricular white matter (PV), posterior limb of the internal capsule (PIC) and cerebral peduncle (CP), and the ratio of N-acetyl-asparte (NAA) to creatine (Cr) were measured at SWM, PV and PIC. Results ALS showed significantly lower FA than controls in the CST, including the SWM, CS, PV and PIC (P0.001). Although there was a trend towards elevated MD in ALS, this did not reach statistical significance. NAA/Cr ratios were also decreased in ALS compared to normal controls (P0.05), with significant differences at the SWM and PV but not in PIC. The T1WI, T2WI, FLAIR of ALS and normal control groups showed that there was no significant difference on MRI between the 2 groups. Conclusion The combination of whole-brain DTI and MRSI can in vivo detect axonal degeneration along CST in ALS patients. Measurements of FA in the SWM, CS, PV and PIC, and NAA/Cr ratios in the SWM and PV can offer the most powerful clues. The MRI changes can not tell ALS from normal control.

OBJECTIVE To observe the effect of nimodipine on the cognition status and the changes of metabolites in brain tissue in the patients with mild cognitive impairment (MCI) in order to evaluate the significance of intervening MCI with medication. METHODS 31 patients with MCI were selected 16 cases were in a treatment group taking nimodipine for 3 months besides taking basic internal medication and 15 cases in a control group taking only basic internal medication. Before and after treatment, multiple cognition tests were carried out in both groups and magnetic resonance spectroscopy (MRS) in Hippocampus region was carried out in 5 patients of the treatment group. RESULTS Verbal instant recall scores, symbol digit modalities test (SDMT) scores and mini-mental state examination (MMSE) total scores in the treatment group were improved significantly after treatment as compared with those in the control group (P < 0.05). CONCLUSION Nimodipine can improve memory ability as well as attention ability of the patients with MCI to a certain extent and make the general cognition function improved.

ObjectiveTo measure cortical areas involved ankle dorsiflexion and planter flexion.MethodsSix-health subjects performed ankle dorsiflexion and planter flexion. While, functional MRI at 1.5 T was made.ResultsWhen ankle dorsiflexion, the excited cortical areas included bilateral primary motor cortex (MⅠ) and primary somatosensory cortex (SⅠ), but area on contralateral side bigger than that on ipsilateral side, as well as chief visual cortexes and vermis of cerebellum. Inhibited areas included area 19, area 20 and area 39. When ankle planter flexion, the excited areas included contralateral secondary motor area (MⅡ) and striate body, ipsilateral supplementary motor area (SMA) and limbic system. Inhibited areas included bilateral upper middle precentral gyrus and postcentral gyrus, superior parietal lobule, inferior parietal lobule and prefrontal cortex.ConclusionThere is a great difference in the brain function images respectively in ankle dorsiflexion and planter flexion.

目的探讨q-空间成像在1.5T 临床用设备上的可行性.方法对12名成年健康志愿者分别用不同的q值进行头部扩散张量成像,通过傅立叶变换得到水分子的位移分布.结果通过对所有被试的平均,能够获得水分子的扩散位移轮廓分布.结论使用q-空间成像可以提供活体内的水分子扩散的定量信息,具有潜在的应用价值.

目的踝关节功能在偏瘫步态中具有重要作用,其功能恢复的好坏与脑病变的部位及大小有密切关系[1,2].许多偏瘫患者在康复后常遗留有踝背屈障碍及跟腱挛缩.神经肌肉电刺激疗法(neuromuscular electrical stimulation,NMES)对偏瘫患者有一定的疗效,与主动运动训练配合具有相互协同的作用,本实验通过对腓总神经电刺激进行脑功能成像的研究,进而对NMES在脑恢复机理方面的作用作一定的探讨.方法健康受试者6人,分别电刺激其腓总神经致踝关节背屈,同时利用1.5T fMRI扫描头颅,所得资料经MRICro软件转换格式,再用SPM99软件进行数据处理及统计学分析(P=0.001).结果兴奋区:对侧第一躯体感觉皮质(primary somatosensory cortex,SⅠ)、第二躯体感觉区(secondary somatosensory area,SⅡ),同侧SⅡ、第二躯体运动区(secondary motor area,MⅡ),以及双侧顶上小叶和顶下小叶;抑制区:按P=0.001标准,双侧均没有阳性结果,按P=0.05标准,则在对侧顶上小叶和顶下小叶交汇处有小片阳性区域,涉及7区.结论腓总神经电刺激致踝关节背屈时对大脑的影响是多方面的,其促进损伤后大脑运动功能的恢复可能是激活了随意运动的中枢编程和感觉性反馈环节.

Motor neuron damage and cortical spinal tract (CST) degeneration are pathological features of amyotrophic lateral sclerosis (ALS). We combined whole-brain diffusion tensor imaging (DTI) and three-dimensional magnetic resonance spectroscopic imaging (MRSI) to study the CST at different locations. Eight ALS patients were compared with normal controls. Fractional anisotropy (FA) and mean diffusivity (MD), and the ratio of N-acetyl-aspartate (NAA) to creatine (Cr) were measured at various locations in the CST, including the subcortical white matter (SWM), centrum semiovale (CS), periventricular white matter (PV), posterior limb of the internal capsule (PIC) and cerebral peduncle (CP). Patients showed significantly lower FA than controls in the CST, including the SWM, CS, PV and PIC. Although there was a trend towards elevated MD in ALS patients, this did not reach statistical significance. NAA/Cr ratios were also decreased in ALS patients compared with normal controls, with significant differences in the SWM and PV but not in PIC. Combined whole-brain DTI and MRSI can detect axonal degeneration in ALS. Measurements of FA obtained in the SWM, CS, PV and PIC, and NAA/Cr ratios in the SWM and PV yield the most robust results.

Objective To observe the changes of the brain function during reading recovery by using functional MRI (fMRI),and to provide the experimental data in elucidating the mechanism on the recovery of reading and language function.Methods fMRI was performed in a native Chinese patient with pure alexia on the 45 th and 130 th day after the onset,respectively.Three kinds of Chinese characters were presented during the scan and the patient was asked to make the judgement weather he could recognize the characters or not.The brain activation maps were acquired after postprocessing,and the activated location and volume were compared between the first and second experiments.Results In both experiments,Broca area,Wernicke area,and the right extrastriate were significantly activated,while the left extrastriate around the lesion was markedly activated only in the second experiment,and the volume of activation in the right extrastriate in the second experiment was about 3 times as large as that in the first experiment.Conclusion The left extrastriate cortex is one of the key areas responsible for reading function in the brain.The recovery of reading function can be compensated in contralateral corresponding cortical area,or it can be the result of reorganization in ipsilateral peri-lesion cortex.Both mechanisms may simultaneously play important roles in reading recovery.

The method of computing diffusion tensor anisotropy index from diffusion on personal computer platform was introduced, and several popular diffusion tensor imaging measurements such as apparent diffusion coefficient, fractional anisotropy, trace, anisotropy index and relative anisotropy were calculated using home-made program based on Matlab program language.

Aim: To investigate the efficacy of functional magnetic resonance imaging (fMRI) in the treatment of patients with intracranial tumors in sensorimotor cortex. Methods: Six patients with tumors in or directly adjacent to the central region were studied with blood oxygen level-dependent (BOLD) fMRI. These data were analyzed to confirm the relationship between the tumor and the sensorimotor cortex. Results: The sensorimotor cortex was confirmed with fMRI in all patients. Total tumor resection were accomplished in 5 patients, and the rest patient of glioma involving frontopariatal region underwent stereotactic biopsy followed by radiotherapy, and no more postoperative neurologic deficits occurred in all patients. Conclusion: fMRI is very useful in assessing the risks of operative intervention and in planning tumor resection.

目的 探索不同b值和扩散张量成像参数的定量关系.方法对12例正常成人进行扩散张量磁共振扫描,测量多个灰白质感兴趣区的表观扩散系数(ADC)、指数表观扩散系数(EADC)、最大特征值、各向异性比率(FA)、各向异性指数(AI)和相对各向异性(RA)等参数,分析这些参数随着b值的变化趋势.结果 FA和RA的平均值、中位数、标准差以及变异系数都不随b值变化(P>0.5);而ADC、EADC及最大特征值受b值的影响(P<0.01),随b值的增加而降低; AI的平均值、中位数、标准差及变异系数在不同被试者间差异存在显著性意义(P<0.05).结论 b值确实影响多个扩散张量成像的导出量.在临床应用中当比较不同被试者,或者不同组织结构时,应尽量选择同样的成像参数,特别是b值,同时选择不受b值影响的参数,如FA和RA。

Objective:To test constraint-induced movement therapy for chronic upper-limb stroke hemiparesis and investigate the neural correlates of recovery with functional magnetic resonance imaging(fMRI)in one subject.Method:Constraint-induced movement therapy consisted of6hour of daily upper-limb training for2week.A restrictive splint was worn on the nonparetic limb during walking hours.fMRI with a1.5T scanner was performed at the time of the subjects attempting sequential finger-tapping at pretreatment,posttreatment and two weeks after treatment.Result:Compared with baseline,the Carroll test improved29.1%,and a Japan upper extremity function test improved18.4%.The Carroll test continued to improve up to30.6%and Japan upper extremity function test improved up to26.2%3months after training.After constrainting the nonparetic limb,the the functional movement didn't decrease.Before training,on fMRI,the activated regions were in the contralateral primary sensorimotor cortex,contralatreral anterior frontal lobe and ipsilateral motor area during the paretic hand movement.Activation in the contralateral primary sensorimotor cortex was found during the nonparetic hand movement.After training,the subject showed scattered activity in ipsilateral and contralateral cortex during the paretic hand movement.Activation in the contralateral primary sensorimotor cortex was found became small during the nonparetic hand movement.2weeks after training,Scattered activity in ipsilateral and contralateral cortex markedly decreased and activated regions were mainly in the contralateral primary sensorimotor cortex during the paretic hand movement.Activation in the contralateral primary sensorimotor cortex was recovery during the nonparetic hand movement.Conclusion:Constraint-induced movement therapy produces significant functional improvement in upper-limb stroke hemiplegia and results in plasticity as demonstrated by fMRI.Constrainting the nonparetic limb have no difference in the functional movement.The change in activated regions in subject's brain is transient.

Segmentation for brain tissue becomes more and more important in clinical diagnosis and treatment for dis-eases as well as for basic research such as for virtual human subjects. In this paper, pattern recognition methods wereused to perform the segmentation for Multi-Spectral MR images. The k Nearest Neighbor (kNN) and the Fuzzy NearestPrototype (FNP) algorithms[1]were adopted. Combination of the consideration on the feature of MR image and the anatomicknowledge, a set of neighborhood rules were established. Generally, kNN and FNP algorithms classify the samples intheir state space, ignoring the information between pixels in the image. The neighborhood rules were added to deter-mine the uncertain results after state space classification. The result from the segmentation was obviously better thenthat from previous kNN or FNP algorithm.

This study has identified the active cerebral areas of normal Chinese that are associated with Chinese semantic processing using functional brain imaging. According to the traditional cognitive theory, semantic processing is not particularly associated with or affected by input modality. The functional brain imaging experiments were conducted to identify the common active areas of two modalities when subjects perform Chinese semantic tasks through reading and listening respectively. The result has shown that the common active areas include left inferior frontal gyrus (BA 44/45), left posterior inferior temporal gyrus (BA37); the joint area of inferior parietal lobules (BA40) and superior temporal gyrus, the ventral occipital areas and cerebella of both hemispheres. It gives important clue to further discerning the roles of different cerebral areas in Chinese semantic processing.

Diffusion Tensor imaging (DTI) can be used to measure the diffusion properties of water molecules.This paper reviews the principle of DTI and summaried the current researches. This paper also presented our primary result about the characteristic MR DTI findings in the brain for the patients with amyotrophic lateral sclerosis(ALS).