采用基于体素的形态测量学方法研究肌萎缩侧索硬化症患者脑灰质的改变

目的 利用基于体素的形态测量学方法(VBM)评价肌萎缩侧索硬化(ALS)患者的脑灰质体积变化及其与临床特征之间的相关性.方法 选取27例ALS患者和年龄、性别匹配的27名正常志愿者,采用VBM分析两组之间的全脑灰质体积和7个先验ROI:包括双侧中央前回,中央后回、额上、中、下回、额内侧回及岛叶灰质体积的改变;以P＜0.05[簇水平错误校正(FWE校正)]为差异有统计学意义.并使用偏相关分析,以年龄为控制因素,提取差异区域平均灰质密度与疾病严重程度评分、病程及疾病进展率进行相关性分析.结果 全脑灰质体积比较显示左侧中央前回、左侧中央后回、左侧额上回局部灰质体积减少,差异有统计学意义(统计体素数目分别为388、112、127,Z值分别为4.83、4.09、6.42,P值均＜0.05,FWE校正).ROI分析显示左侧中央前回、右侧中央前回、左侧中央后回、左侧额上回和左侧岛叶灰质体积减少,差异有统计学意义(统计体素数目分别为1104、34、114、91、107,Z值分别为5.87、3.71、4.26、6.29、3.51,P值均＜0.05,FWE校正).所有局部灰质体积减少程度与各临床指标间未发现有统计学差异的线性关系.结论 ALS可出现运动皮层及非运动皮层多个脑区灰质体积减少,进一步证实ALS系一种多系统变性病.相对于全脑比较,ROI分析能敏感地揭示更广泛的脑区改变.VBM所揭示的结构改变与临床指标之间缺乏相关性,考虑与病情本身的异质性和方法学的敏感性有关.     

Comparison of grey matter atrophy between patients with neuromyelitis optica and multiple sclerosis: a voxel-based morphometry study

Purpose

Previous studies have established regional grey matter (GM) loss in multiple sclerosis (MS). However, whether there is any regional GM atrophy in neuromyelitis optica (NMO) and the difference between NMO and MS is unclear. The present study addresses this issue by voxel-based morphometry (VBM).

Methods

Conventional magnetic resonance imaging (MRI) and T1-weighted three-dimensional MRI were obtained from 26 NMO patients, 26 relapsing–remitting MS (RRMS) patients, and 26 normal controls. An analysis of covariance model assessed with cluster size inference was used to compare GM volume among three groups. The correlations of GM volume changes with disease duration, expanded disability status scale (EDSS) and brain T2 lesion volume (LV) were analyzed.

Results

GM atrophy was found in NMO patients in several regions of frontal, temporal, parietal lobes and insula (uncorrected, p < 0.001). While extensive GM atrophy was found in RRMS patients, including most cortical regions and the deep grey matter (corrected for multiple comparisons, p < 0.01). Compared with NMO, those with RRMS had significant GM loss in bilateral thalami, caudate, left parahippocampal gyrus, right hippocampus and insula (corrected, p < 0.01). In RRMS group, regional GM loss in right caudate and bilateral thalami were strongly correlated with brain T2LV.

Conclusions

Our study found the difference of GM atrophy between NMO and RRMS patients mainly in deep grey matter. The correlational results suggested axonal degeneration from lesions on T2WI may be a key pathogenesis of atrophy in deep grey matter in RRMS.     

Brain atrophy in relapsing-remitting multiple sclerosis: fractional volumetric analysis of gray matter and white matter

PURPOSE: To determine the fractional brain tissue volume changes in the gray matter and white matter of patients with relapsing-remitting multiple sclerosis (MS) and to correlate these measurements with clinical disability and total lesion load. MATERIALS AND METHODS: Thirty patients with relapsing-remitting MS and 25 healthy control subjects underwent magnetic resonance imaging. Fractional brain tissue volumes (tissue volume relative to total intracranial volume) were obtained from the total segmented gray matter and white matter in each group and were analyzed. RESULTS: The fractional volume of white matter versus that of gray matter was significantly lower (-6.4%) in patients with MS (P <.0001) than in control subjects. Neither gray matter nor white matter fractional volume measurements correlated with clinical disability in the patients with MS. CONCLUSION: Loss of brain parenchymal volume in patients with relapsing-remitting MS is predominantly confined to white matter. Analysis of fractional brain tissue volumes provides additional information useful in characterizing MS and may have potential in evaluating treatment strategies.     

应用优化的基于体素的形态测量学方法显示强迫症患者脑灰质异常

目的 运用优化的基于体素的形态学方法(VBM)研究中国汉族人群强迫症(OCD)患者脑灰质结构异常以及与临床症状的相关性.方法 选取20例OCD患者和年龄、性别匹配的20名正常对照者,进行高分辨3.0 T MR扫描,在统计参数图(SPM)5软件中采用优化的VBM方法处理三维T1结构像,然后比较OCD患者与正常对照组脑灰质体积的差异.并提取代表OCD患者有差异脑区体积平均值的特征值,与临床评分以及病程进行Pearson相关性分析.结果 与正常对照组相比,经过错误发现率(FDR)校正,OCD患者双侧丘脑以及左侧小脑的灰质体积增大,同时没有发现OCD患者相对正常对照组灰质体积减小的区域.代表OCD患者左侧丘脑体积特征值为0.5782～0.8890,平均为0.6813±0.0718,右侧丘脑体积特征值为0.5546～0.9062,平均为0.6869±0.0808,两者呈正相关(r=0.94,P＜0.01).结论 运用优化的VBM方法发现,OCD患者双侧丘脑及左侧小脑灰质体积增加,为OCD患者临床症状学的差异提供了脑结构的神经影像学证据,提示双侧丘脑以及小脑在OCD发生的病理生理机制当中具有重要作用.

Abstract：

Objective To explore changes of gray matter volume in patients with obsessivecompulsive disorder (OCD) in Chinese Han population using optimized voxel-based morphometry (VBM) ,and investigate its relationship with clinical symptoms. Methods Twenty patients with OCD and 20 age,sex and handedness matched healthy controls were scanned using 3D-T1 images on a 3.0 T MR system. The high resolution T1WI was preprocessed according to the optimized VBM protocol in Statistical Parametric Mapping (SPM5). Two-sample t test was performed to characterize the differences of the gray matter volume (GMV) between the OCD patients and healthy controls, and the correlations between the GMV and symptom severity and cumulative illness duration were examined using Pearson correlation in SPSS 16. 0, respectively.Results Compared to controls, OCD patients demonstrated increased GMV in left thalamus, right thalamus and left cerebellum after false discovery rate (FDR) correction. No areas of significantly decreased GMV was observed in OCD patients in relative to healthy controls. The mean eigenvalue ranged from 0. 5782 to 0. 889 representing the left thalamus volume of OCD patients was 0. 6813 ± 0. 0718, and that ranged from 0. 5546 to 0. 9062 was 0. 6869 ± 0. 0808 tor right thalamus. The mean eigenvalues were positively correlated in bilateral thalamus (r = 0. 94, P ＜ 0. 01). Conclusion Using optimized VBM, the current research indicates that the pathophysiology of OCD is associated with GMV abnormalities not only in corticostriato-thalamo-cortical (CSTC) circuit, but also in the cerebellum.     

帕金森病的脑灰质体积改变的VBM研究

目的 分析帕金森病(PD)患者的全脑灰质体积的变化,探讨PD患者的脑灰质结构异常模式.方法 选取符合入组标准的46例PD患者和19例年龄、性别与之相匹配的正常对照(NC)被试者作为研究对象.46例PD患者按改良的Hoehn-Yahr (H-Y)分级标准又分为2个亚组,25例早期PD(ePD)组和21例中晚期PD(maPD)组.所有受试者在3.0T超高场磁共振仪进行常规磁共振扫描,并获取三维高分辨T1WI数据,采用VBM-DARTEL(voxel-based morphometry-diffeomorphic anatomical registration through exponentiated lie)方法分析比较PD组与NC组、ePD组与maPD组间的脑灰质体积差异.结果 与NC组相比,PD组双侧额叶、颞叶、岛叶、扣带回、海马、梭状回、小脑及右侧楔叶、楔前叶等脑区的灰质体积减小,全脑灰质未见体积增加.与ePD组相比,maPD组双侧额叶、颞叶、岛叶、扣带回、直回、舌回、梭状回、海马、杏仁核及小脑等脑区的灰质体积减小.结论 VBM方法客观提示了PD存在广泛的脑灰质萎缩,且随病程的进展更为显著.PD脑结构的变化存在特定的空间分布模式,可能与PD的病理基础有关.     

应用优化的基于体素的形态测量学方法显示强迫症患者脑灰质异常

Objective To explore changes of gray matter volume in patients with obsessivecompulsive disorder (OCD) in Chinese Han population using optimized voxel-based morphometry (VBM) ,and investigate its relationship with clinical symptoms. Methods Twenty patients with OCD and 20 age,sex and handedness matched healthy controls were scanned using 3D-T1 images on a 3.0 T MR system. The high resolution T1WI was preprocessed according to the optimized VBM protocol in Statistical Parametric Mapping (SPM5). Two-sample t test was performed to characterize the differences of the gray matter volume (GMV) between the OCD patients and healthy controls, and the correlations between the GMV and symptom severity and cumulative illness duration were examined using Pearson correlation in SPSS 16. 0, respectively.Results Compared to controls, OCD patients demonstrated increased GMV in left thalamus, right thalamus and left cerebellum after false discovery rate (FDR) correction. No areas of significantly decreased GMV was observed in OCD patients in relative to healthy controls. The mean eigenvalue ranged from 0. 5782 to 0. 889 representing the left thalamus volume of OCD patients was 0. 6813 ± 0. 0718, and that ranged from 0. 5546 to 0. 9062 was 0. 6869 ± 0. 0808 tor right thalamus. The mean eigenvalues were positively correlated in bilateral thalamus (r = 0. 94, P ＜ 0. 01). Conclusion Using optimized VBM, the current research indicates that the pathophysiology of OCD is associated with GMV abnormalities not only in corticostriato-thalamo-cortical (CSTC) circuit, but also in the cerebellum.     

应用优化的基于体素的形态测量学方法显示强迫症患者脑灰质异常

Objective To explore changes of gray matter volume in patients with obsessivecompulsive disorder (OCD) in Chinese Han population using optimized voxel-based morphometry (VBM) ,and investigate its relationship with clinical symptoms. Methods Twenty patients with OCD and 20 age,sex and handedness matched healthy controls were scanned using 3D-T1 images on a 3.0 T MR system. The high resolution T1WI was preprocessed according to the optimized VBM protocol in Statistical Parametric Mapping (SPM5). Two-sample t test was performed to characterize the differences of the gray matter volume (GMV) between the OCD patients and healthy controls, and the correlations between the GMV and symptom severity and cumulative illness duration were examined using Pearson correlation in SPSS 16. 0, respectively.Results Compared to controls, OCD patients demonstrated increased GMV in left thalamus, right thalamus and left cerebellum after false discovery rate (FDR) correction. No areas of significantly decreased GMV was observed in OCD patients in relative to healthy controls. The mean eigenvalue ranged from 0. 5782 to 0. 889 representing the left thalamus volume of OCD patients was 0. 6813 ± 0. 0718, and that ranged from 0. 5546 to 0. 9062 was 0. 6869 ± 0. 0808 tor right thalamus. The mean eigenvalues were positively correlated in bilateral thalamus (r = 0. 94, P ＜ 0. 01). Conclusion Using optimized VBM, the current research indicates that the pathophysiology of OCD is associated with GMV abnormalities not only in corticostriato-thalamo-cortical (CSTC) circuit, but also in the cerebellum.     

Increased gray matter density in the parietal cortex of mathematicians: a voxel-based morphometry study

BACKGROUND AND PURPOSE: The training to acquire or practicing to perform a skill, which may lead to structural changes in the brain, is called experience-dependent structural plasticity. The main purpose of this cross-sectional study was to investigate the presence of experience-dependent structural plasticity in mathematicians' brains, which may develop after long-term practice of mathematic thinking. MATERIALS AND METHODS: Twenty-six volunteer mathematicians, who have been working as academicians, were enrolled in the study. We applied an optimized method of voxel-based morphometry in the mathematicians and the age- and sex-matched control subjects. We assessed the gray and white matter density differences in mathematicians and the control subjects. Moreover, the correlation between the cortical density and the time spent as an academician was investigated. RESULTS: We found that cortical gray matter density in the left inferior frontal and bilateral inferior parietal lobules of the mathematicians were significantly increased compared with the control subjects. Furthermore, increase in gray matter density in the right inferior parietal lobule of the mathematicians was strongly correlated with the time spent as an academician (r = 0.84; P < .01). Left-inferior frontal and bilateral parietal regions are involved in arithmetic processing. Inferior parietal regions are also involved in high-level mathematic thinking, which requires visuospatial imagery, such as mental creation and manipulation of 3D objects. CONCLUSION: The voxel-based morphometric analysis of mathematicians' brains revealed increased gray matter density in the cortical regions related to mathematic thinking. The correlation between cortical density increase and the time spent as an academician suggests experience-dependent structural plasticity in mathematicians' brains.     

采用基于体素的形态测量学比较分析不同核型特纳综合征患儿全脑灰质的变化

目的 利用基于体素的形态测量学(VBM)方法,探测不同核型特纳综合征(TS)患儿脑灰质体积异常的差异.方法 19例染色体核型为45XO的单体型TS患儿和21例杂合核型的TS患儿以及20名正常儿童(对照组)进行了韦氏智力测量和3.0TMR扫描.单体型TS患儿组、杂合型TS患儿组和对照组的全脑高分辨率T1WI图像采用统计参数图(SPM)8软件包进行VBM分析,以全脑灰质总体积为协变量,比较3组之间全脑灰质体积的差别,采用功能神经图像分析软件AFNI软件包中的蒙特卡洛模拟方法(AlphaSim方法)进行簇水平上的多重比较校正.结果 单体型TS组患儿韦氏总智商值为(89±16)分,杂合型TS组为(91±13)分,而对照组韦氏总智商值为(109±15)分,3组智商差异具有统计学意义(F=10.75,P＜0.05).与对照组比较,单体型TS组及杂合型TS组均表现双侧楔叶、中央后回、扣带回灰质体积减小,差异有统计学意义(单体型TS组统计区体素数目分别4117、1392、1085,t值分别为5.75、5.33、5.02;杂合型TS组统计区体素数目为4501、2437、591,t值分别为5.40、5.11、4.95,P值均＜0.01,FWE校正);两组TS患儿均在眶额回、海马旁回、小脑、岛叶,右侧颞极、纹状体,中脑背侧灰质体积增加,差异有统计学意义(单体型TS组统计区体素数目分别为1444、1188、791、725、695、431、386,t值分别为5.01、5.96、5.67、5.23、4.85、4.43、4.94;杂合型TS组统计区体素数目分别为6988、2709、2510、2380、1987、1709、1185,t值分别为6.50、7.06、7.26、5.27、5.71、6.02、4.56,P值均＜0.01,FWE校正).单体型TS组与杂合型TS组比较,杂合型TS组在左侧海马、纹状体较单体型TS组灰质体积增加(体素数目分别为1014、496,中心坐标t值分别为4.75和4.53,P值均＜0.01,FWE校正),在右侧缘上回灰质体积减少(体素数目为350,中心坐标t值为4.28,P＜0.01,FWE校正),差异有统计学意义.结论 单体型与杂合型TS患儿均存在顶枕叶的萎缩,说明单体型与杂合型TS导致的脑皮层发育障碍类似;而杂合型TS患儿双侧前额叶、颞叶与小脑的体积增加区域较单体型更为广泛,提示杂合型TS可能更多利用这些脑区进行代偿.     

单体型特纳综合征患儿全脑灰、白质基于体素的形态学分析

目的 利用基于体素的形态测量学(VBM)方法,探测单体型特纳综合征(TS)患儿脑灰、白质体积的异常.方法 选取9例染色体核型为45XO的单体型TS患儿(TS组)和20名正常女童(对照组),进行了韦氏智力测量和3.0TMR扫描.TS组和对照组的全脑高分辨率T1WI采用统计参数图SPM 8软件包进行VBM分析,以全脑灰、白质总体积为协变量,以协方差分析比较单体型TS患儿和对照组之间全脑灰、白质体积的差别,采用功能神经图像分析软件包(AFNI)中的蒙特卡洛模拟方法(即AlphaSim方法)进行簇水平上的多重比较校正.结果 TS组患儿韦氏总智商值为81±13,而对照组儿童韦氏总智商值为109±16,两组儿童智商差异具有统计学意义(t=-4.70,P＜0.05).与对照组比较,单体型TS患儿右侧顶上小叶、中央后回、楔叶、楔前叶、距状皮层,左侧枕叶中下部灰质体积减小,差异有统计学意义(统计区体素数目分别为631、525、520个,t值分别为3.95、3.50、3.36,P值均＜0.05);双侧辅助运动区、额上回内侧,右侧扣带回中部,左侧颞上、中、下回,左侧额上、中、下回,左侧小脑,左侧海马、海马旁回,左侧梭状回灰质体积增加,差异有统计学意义(统计区体素数目分别为2082、974、1708、588、579个,t值分别为5.45、4.59、4.40、4.29、3.55,P值均＜0.05).白质体积比较的结果表明,单体型TS患儿左侧中央后回及顶下小叶的白质体积较对照组减小,差异具有统计学意义(体素数目957,t=5.85,P＜0.05).结论 TS患儿存在脑灰、白质发育的异常,该异常改变可能是单体型TS患儿认知功能障碍的神经病理学基础.     

Cerebral and cerebellar gray matter reduction in first-episode patients with major depressive disorder: A voxel-based morphometry study

Purpose

To investigate cerebral and cerebellar gray matter abnormalities in patients with first-episode major depressive disorder (MDD).

Materials and methods

We examined the structural difference in regional gray matter density (GMD) between 22 first-episode MDD patients and 30 age-, gender- and education-matched healthy controls by optimized voxel-based morphometry (VBM) based on magnetic resonance imaging.

Results

Compared with healthy controls, MDD patients showed decreased GMD in the right medial and left lateral orbitofrontal cortex, right dorsolateral prefrontal cortex (DLPFC), bilateral temporal pole, right superior temporal gyrus, bilateral anterior insular cortex, left parahippocampal gyrus, and left cerebellum. In addition, in MDD patients, there was a negative correlation between GMD values of the right DLPFC and the score of the depression rating scale.

Conclusions

Our findings provided additional support for the involvement of limbic-cortical circuits in the pathophysiology of MDD and preliminary evidence that a defect involving the cerebellum may also be implicated.     

采用优化的基于体素的形态学方法研究智力障碍儿童脑灰质容积变化

目的 利用优化的基于体素的形态测量学(VBM)方法,比较病因不明且常规影像检查正常的智力障碍儿童与正常同龄儿童脑灰质容积的差异,探究患儿脑灰质发育与智力障碍间的联系.方法 选取21例智力障碍患儿和30名正常儿童进行高分辨率脑MR扫描,然后进行VBM分析,应用独立样本t检验比较两组儿童脑灰质容积总量以及不同区域灰质容积的差别.同时,对智力障碍儿童的智商评分与脑灰质容积总量进行偏相关性分析.结果 智障儿童脑灰质容积总量[(1.012±0.079)×106 mm3]明显大于正常儿童[(0.956±0.059)×106mm3],智障组与正常对照组儿童脑灰质总容积的差异具有统计学意义(t=-2.80,P＜0.05).智障组儿童脑局部区域灰质容积较正常对照组高,脑区包括双侧丘脑、额上回、直回和颞极,以及右侧额下回、海马旁回和右侧小脑.智障组儿童脑灰质容积与智商无相关性(r=0.078,P＞0.05).结论 VBM能够显示常规MRI表现正常的智力障碍儿童中的脑灰质发育异常.额叶-丘脑环路的脑灰质容积增加,提示其发育滞后,可能是导致儿童智力障碍的原因之一.

Abstract：

Objective To detect brain structural difference between children with unexplained mental retardation and children with typically normal development. Methods The high-resolution magnetic MR imaging were obtained from 21 children with unexplained mental retardation and 30 age-matched control children without intellectual disabilities. Voxel-based morphometry analysis with an optimization of spatial segmentation and normalization procedures were applied to compare differences of gray matter volume between the two groups. The total and regional gray matter volume were compared between the two groups with independent t test. Meanwhile, correlation was conducted to analyze the relationship between the total gray matter volume and intelligence quotient (IQ) with partial correlation test. Results The total gray matter volume was significantly increased in the mental retardation children [(1. 012 ±0. 079) × 106 mm3]in relative to the controls [(0. 956 ± 0. 059) × 106 mm3, t = - 2. 80, P ＜ 0. 05]. Compared to controls,children with unexplained mental retardation showed significantly increased gray matter volume in different regions, including the bilateral thalami, the bilateral superior frontal gyri, the bilateral gyri rectus, the bilateral temporal poles, the right inferior frontal gyrus, right parahippocampal gyrus and the right cerebellum. No correlation was detected between the total gray matter volume and IQ in children with mental retardation (r = 0. 078 ,P ＞ 0. 05). Conclusions VBM would detect the gray matter abnormalities that were not founded in routine MR scanning. The increase of gray matter volume in the frontal-thalamus network might indicate the delayed maturation of the brain development. This might be one of the causations of mental retardation in children.     

应用基于体素的MR形态测量学分析抽动秽语综合征患儿脑灰质体积变化

目的 应用优化的基于体素的形态测量学(VBM)技术,分析抽动秽语综合征(TS)患儿全脑灰质异常情况.方法 选取31例TS患儿(TS组)和与之年龄、性别匹配的50名正常儿童(正常对照组)进行3DT1WI.利用基于统计参数图(SPM)2软件的VBM 2工具箱对扫描获得的图像进行预处理,对TS患儿和正常儿童的全脑灰质体积采用t检验进行比较.将灰质体积差异区域的改变值提取出来,与临床耶鲁综合抽动严重程度评分量表(YGTSS)评分、病程进行多元线性分析.结果 应用VBM方法,发现TS组的左顶上小叶、右小脑半球、左海马旁回灰质体积较对照组增大,增加体积分别为4059、2126、84 mm3,其差异有统计学意义(t值分别为3.93、3.71、3.58,P值均＜0.05).延髓和左桥脑体积较对照组减小,减小体积分别为213、117 mm3(t值分别为3.53、3.48,P值均＜0.05).体积差异区域的体积改变值与临床YGTSS评分无相关性(P＞0.05),左海马旁回灰质体积与患儿病程呈负相关(Beta=-0.391,P=0.039).结论 VBM能够显示常规MRI表现正常的TS患儿的灰质异常.颡顶叶和小脑体积增加可能是TS患儿的适应性反应,左海马旁回灰质体积可能是评价TS患者预后的一项客观指标.     

采用优化的基于体素的形态学方法研究智力障碍儿童脑灰质容积变化

Objective To detect brain structural difference between children with unexplained mental retardation and children with typically normal development. Methods The high-resolution magnetic MR imaging were obtained from 21 children with unexplained mental retardation and 30 age-matched control children without intellectual disabilities. Voxel-based morphometry analysis with an optimization of spatial segmentation and normalization procedures were applied to compare differences of gray matter volume between the two groups. The total and regional gray matter volume were compared between the two groups with independent t test. Meanwhile, correlation was conducted to analyze the relationship between the total gray matter volume and intelligence quotient (IQ) with partial correlation test. Results The total gray matter volume was significantly increased in the mental retardation children [(1. 012 ±0. 079) × 106 mm3]in relative to the controls [(0. 956 ± 0. 059) × 106 mm3, t = - 2. 80, P ＜ 0. 05]. Compared to controls,children with unexplained mental retardation showed significantly increased gray matter volume in different regions, including the bilateral thalami, the bilateral superior frontal gyri, the bilateral gyri rectus, the bilateral temporal poles, the right inferior frontal gyrus, right parahippocampal gyrus and the right cerebellum. No correlation was detected between the total gray matter volume and IQ in children with mental retardation (r = 0. 078 ,P ＞ 0. 05). Conclusions VBM would detect the gray matter abnormalities that were not founded in routine MR scanning. The increase of gray matter volume in the frontal-thalamus network might indicate the delayed maturation of the brain development. This might be one of the causations of mental retardation in children.     

Whole-brain voxel-based morphometry of white matter in mild cognitive impairment

Purpose

The purpose of this study was to analyze whole-brain white matter changes in mild cognitive impairment (MCI).

Materials and methods

We studied 14 patients with MCI and 14 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The data were collected on a 3T MR system and analyzed by SPM2 to generate white matter volume maps.

Results

Voxel-based morphometry revealed diffusively reduced white matter in MCI prominently including the bilateral temporal gyrus, the right anterior cingulate, the bilateral superior and medial frontal gyrus and right parietal angular gyrus. White matter reduction was more prominent in anterior regions than that in posterior regions.

Conclusion

Whole-brain white matter reduction in MCI patients detected with VBM has special distribution which is in line with the white matter pathology of MCI.     

肌萎缩侧索硬化症基于体素的形态测量扩散张量分析

目的 利用基于体素的形态测量学(VBM)及基于体素的扩散张量分析评价肌萎缩侧索硬化症(ALS)患者的脑灰质、白质体积及各向异性分数(FA)值的改变.方法 选取39例确诊或拟诊为ALS的患者(ALS组)及39名健康成年人(对照组)进行常规MR扫描及神经心理学评估,并采集3D快速扰相梯度回波(fast spoiled gradient echo,FSPGR)序列T_1WI和DTI数据.对3D T_1结构像进行配准、分割、平滑后,采用VBM分析,计算分割后的脑灰质、白质及脑脊液的体积.选取76名健康志愿者进行DTI,对原始图像进行后处理,制作FA模版,将ALS组和对照组受试者的FA图配准在所创建的FA模版上,测量FA值.统计方法采用协方差分析,因性别完全匹配,故对于VBM,年龄及全脑总体积作为协变量,而对于基于体素的扩散张量分析,仅年龄作为协变量,P＜0.01(未校正),相连像素＞20个的脑区为有差异的脑区.结果 全脑体积分析显示两组受试者的全脑灰质体积、全脑白质体积、全脑体积及脑灰质分数之间差异无统计学意义,但ALS患者的白质分数(0.29±0.02)小于健康对照组(0.30±0.02)(P=0.003).与健康对照组比较,ALS患者局部灰质体积减少脑区主要位于双侧额上回及中央前回,右侧额中回及颞中、下回,左侧枕上回、楔叶及左侧岛叶,ALS患者局部白质体积减少脑区主要位于胼胝体膝部,双侧额内侧回、旁中央小叶及岛叶,右侧额上回及额中回、左侧中央后回.ALS患者双侧扣带回及海马旁回FA值较对照组减低.结论 ALS并不是单纯的运动神经元病,是一种多系统受累的疾病,基于体素的扩散张量分析对于怀疑认知功能障碍的患者海马旁回及扣带回白质FA值变化的检出具有一定的潜在价值.     

Radiation-induced changes in normal-appearing gray matter in patients with nasopharyngeal carcinoma: a magnetic resonance imaging voxel-based morphometry study

Introduction

Evidence is accumulating that temporal lobe radiation necrosis in patients with nasopharyngeal carcinoma (NPC) after radiotherapy (RT) could involve gray matter (GM). The purpose of the study was to assess the radiation-induced GM volume differences between NPC patients who had and had not received RT and the effect of time after RT on GM volume differences in those patients who had received RT.

Methods

We used magnetic resonance imaging voxel-based morphometry (VBM) to assess differences in GM volume between 30 NPC patients with normal-appearing whole-brain GM after RT and 15 control patients with newly diagnosed but not yet medically treated NPC. Correlation analyses were used to investigate the relationship between GM volume changes and time after RT.

Results

Patients who had received RT had GM volume decreases in the bilateral superior temporal gyrus, left middle temporal gyrus, right fusiform gyrus, right precentral gyrus, and right inferior parietal lobule (p?<?0.001, uncorrected, cluster size >100 voxels). Moreover, the correlation analysis indicated that regional GM volume loss in the left superior temporal gyrus, left middle temporal gyrus, and right fusiform gyrus were negatively related to the mean dose to the ipsilateral temporal lobe, respectively.

Conclusion

These results indicate that GM volume deficits in bilateral temporal lobes in patients who had received RT might be radiation-induced. Our findings might provide new insight into the pathogenesis of radiation-induced structural damage in normal-appearing brain tissue. Yet this is an exploratory study, whose findings should therefore be taken with caution.     

Whole-brain voxel-based morphometry of white matter in medial temporal lobe epilepsy

PURPOSE: The purpose of this study was to analyze whole-brain white matter changes in medial temporal lobe epilepsy (MTLE). MATERIALS AND METHODS: We studied 23 patients with MTLE and 13 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The seizure focus was right sided in 11 patients and left sided in 12. The data were collected on a 1.5 T MR system and analyzed by SPM 99 to generate white matter density maps. RESULTS: Voxel-based morphometry revealed diffusively reduced white matter in MTLE prominently including bilateral frontal lobes, bilateral temporal lobes and corpus callosum. White matter reduction was also found in the bilateral cerebellar hemispheres in the left MTLE group. CONCLUSION: VBM is a simple and automated approach that is able to identify diffuse whole-brain white matter reduction in MTLE.