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.     

高分辨MR结构成像幼儿皮层特征参数与智力发育相关性的初步研究

目的：应用基于高分辨MRI结构成像（sMRI）、表面基础形态测量学（sBM）的皮层测量方法,分析幼儿148个脑区的皮层厚度（CT）、皮层表面积（sA）及平均曲率（AV）等参数,探讨皮层厚度等皮层形态学参数与幼儿智力发育水平的相关性。方法：对13例健康幼儿受试者进行智力发育水平评分。采用Siemens3．0TMR机对所有纳入对象进行高分辨率的3DT。脑结构图像采集。使用基于SBM的方法获取每个被试者148个脑区的CT、SA、AV等参数,逐一对每个脑区皮层参数与幼儿智力发育水平评分进行相关性分析。结果：对受试者大脑半球皮层参数与智力量表评分的相关性分析中发现,sA与智力量表评分存在相关性的脑区集中于语言及社交相关区,即额下回脑沟局部区域,大部分呈负相关,如右脑额下回sA与量表中适应性评分的相关系数r=-0．646（P=0．017）,与量表中语言评分的相关系数值r=0．576（P=0．039）;AV与智力量表评分存在相关性的脑区集中于视听、高级整合功能区的颞下回及顶下区,大部分呈负相关,如颞下回AV与量表中精细动作评分的相关系数r=-0．716（P=0．002）;而CT与智力量表评分相关的脑区主要为语言区及与人脸识别相关的侧副横沟前部脑区,呈负相关,如右脑侧副横沟前部CT与量表中语言评分的r值为一0．765（P=0．002）。结论：基于高分辨率MRI并采用SBM测量的幼儿皮层参数与基于智力量表的幼儿智力评分间存在相关性的脑区分布比较广泛,由此可知幼儿大脑结构发育受内在生理因素影响,这与幼儿的智力发育水平、社会适应能力有直接关系。利用这种方法可以对幼儿脑皮层结构进行评估,并可进一步推测幼儿的基本发育状况。     

未经治疗的首发精神分裂症患者脑灰质非对称性改变:基于VBM的MRI结构研究

目的:采用核磁共振成像及优化的基于体素形态学研究(voxel based morphometry,VBM)新技术分析未经治疗的首发精神分裂症患者的脑结构非对称性改变。方法:对符合DSM-IV精神分裂症诊断标准,同时未经药物治疗的首发精神分裂症住院患者以及正常志愿者各20例进行核磁共振扫描脑结构成像及基于VBM的脑非对称性分析。结果:病例组较正常对照显示出明显的正常非对称性减低甚至反转的改变。正常右利手左半球优势区域如额上回、颞中回、扣带回、眶回、尾状核头以及丘脑的非对称性下降;中央后回非对称性反转;海马及海马旁回的右大于左的非对称性增加。结论:脑非对称性在未用药物治疗的首发精神分裂症患者中有明显的异常改变,提示精神分裂症患者存在原发的脑结构非对称性异常,脑非对称性紊乱的存在反映了神经异常发育与精神分裂症的发病的关联。精神分裂症患者存在的脑结构非对称性异常可能构成了精神分裂症的神经生物学表征。     

脑功能磁共振成像的质量控制标准

自1972年第一台磁共振扫描仪问世以来,磁共振作为一项重要的临床检查手段得到了飞速的发展[1]。同时,磁共振的成像方式也与日俱进:multi-echo SE,fast spin-echo,gradient-echo,EPI,ASSET,DTI等序列的相继问世[2,3],开辟了磁共振科研的新天地。但是,作为一种非常复杂的系统,磁共振仪器的成像受很多因素和环节的影响[4,5]。任何一个环节的出错,都可能影响图像质量。在国外,从事磁共振质量控制的是专门的磁共振工程师[6,7]。国内通常由放射技师和物理师共同完成该工作。据统计显示,我国目前磁共振仪器的运行状况并未完全达标[8]。这就迫切需要一套专门针对磁共振仪器质量控制的、简单易行的标准。由于磁共振成像的复杂性,磁共振的质量控制也涉及诸多方面[9]。1 signal to noise ratio(SNR)磁共振是一种信号成像,包括了有用的图像的整体噪声,用图像中心区域的信号值作为整体信号[10]。1·1常规SNR的测量方式(图1):信号(信息)和无用的信号(噪声)。SNR越高,则图像质量越好。目前磁共振头部线圈多采用相控阵线圈,这种线圈有多个信号接收单元,图像各个部...     

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.     

正常成人吞咽时的脑激活区域：功能磁共振初步研究

BACKGROUND： While brain-imaging studies in healthy adults have indicated that multiple cortical regions are involved in swallowing, these functional imaging techniques have not been extensively applied to the complete understand neurophysiology of swallowing in China. A full understanding of normal swallowing neurophysiology is important for improving functional outcomes for dysphagia due to neurologic disorders or damage with increasing age. Thus the interpretations of the functional contributions of various brain areas in swallowing should be scientifically researched. OBJECTIVE： To identify the activation and characteristic of swallowing center in healthy adults using functional magnetic resonance imaging. DESIGN, TIME AND SETTING： An uncontrolled neuroimaging study was performed at the Outpatient Clinic, Department of Radiology, West China Hospital of Sichuan University between March and November 2008. PARTICIPANTS： Ten healthy right-handed volunteers, aged over 20 years with a mean age of （34.2 ＋ 8.1） years, a range of 25-45 years and including five males and five females participated. A medical history was obtained from all potential subjects and all subjects were free of systemic diseases and neurological disorders. METHODS： The healthy volunteers were examined with event-related functional magnetic resonance imaging of blood oxygenation level-dependent while laryngeal swallow-related movements were recorded. Subjects were scanned during voluntary saliva swallowing and water bolus swallowing activation tasks. Data was processed using the General Linear Model. A voxel by voxel group comparison was performed using random effect analysis. Any cluster with a corrected P 〈 0.05 for spatial extent was considered significant. MAIN OUTCOME MEASURES： The cerebral cortical activation maps of voluntary swallowing of saliva and swallowing of water bolus in healthy adults were observed. RESULTS： A multifocal cortical representation of swallowing was in the precentral gyrus, postcentral gyrus, insula, anterior cingulate gyrus, thalamus, basal ganglia and cerebellum, in a bilateral and asymmetrical manner, predominantly on the left hemisphere in the volunteers （P 〈 0.05）. CONCLUSION： Activation of the cortex during normal swallowing tasks may be functionally linked to basal nuclei, thalamus, and cerebellum, greatly appearing in the left hemisphere.     

创伤后应激障碍患者静息态下脑功能局部一致性的研究

目的利用局部一致性(ReHo)方法探测创伤后应激障碍(PTSD)患者在静息状态下是否存在着大脑功能异常。方法 2010年5月-7月对18例未经治疗的地震PTSD患者和19例同样经历地震但未患PTSD的对照者进行了静息态功能磁共振成像(Rs-fMRI)扫描。应用ReHo方法处理Rs-fMRI数据,得出PTSD患者的异常脑区,并将患者存在组间差异的脑区ReHo值与临床用PTSD诊断量表(CAPS)、汉密尔顿抑郁量表(HAMD)和汉密尔顿焦虑量表(HAMA)分别进行相关分析。结果①PTSD组ReHo显著增加的脑区包括右侧颞下回、楔前叶、顶下叶、中扣带回,左侧枕中回以及左/右侧后扣带回;ReHo显著降低的脑区包括左侧海马和左/右侧腹侧前扣带回。②异常脑区中后扣带回和右侧中扣带回ReHo与HAMD呈负相关(中扣带回r=0.575,P=0.012;右侧后扣带回:r=0.507,P=0.032),其余脑区ReHo与临床指标无明显相关性(P>0.05),左侧海马与CAPS的相关性相对其他脑区较大(r=0.430,P=0.075)。结论 PTSD患者在静息状态下即存在着局部脑功能活动的降低和增加,ReHo方法可能有助于研究PTSD患者静息状态脑活动。     

脑结构形态学改变是精神分裂症的遗传内表型

目的 通过对首发精神分裂症患者及其未患病同胞的磁共振成像脑结构分析,探讨遗传因素对脑结构改变的影响程度,为发现精神分裂症的遗传内表型提供实验依据.方法 采用优化的基于体素的形态学研究方法对15例首发精神分裂症患者、19名首发精神分裂症患者未患病同胞及38名正常对照的大脑磁共振图像进行处理,采用一般线性模型进行统计分析.结果 与正常对照组相比,患者组在双侧颢叶、双侧枕叶、左侧岛叶、左侧额叶额上回及右豆状核苍白球灰质有明显减少;在双侧顶叶及双侧边缘叶扣带回灰质增加;未患病同胞组在右侧颞叶、双侧枕叶、左侧岛叶及左侧额叶中央前回等区域灰质明显减少;在左侧顶叶及双侧小脑后叶灰质增加.患者较同胞左侧顶叶楔前叶灰质有增加,未发现两者其他区域存在明显差异.结论 精神分裂症患者及其同胞存在相似的脑结构异常,遗传因素可能是导致精神分裂症脑结构异常的重要因素,提示脑结构形态学改变是精神分裂症的遗传内表型.     

家族性和散发性首发精神分裂症患者及其父母的脑结构差异

目的应用优化的基于体素的形态学研究方法(voxel based morphometry,VBM)比较家族性和散发性首发精神分裂症患者及其父母的脑结构差异。方法纳入家族性精神分裂症患者10例,其父母8例;散发性精神分裂症患者10例,其父母12例。同时纳入20例正常对照。采用优化的VBM方法处理高分辨T1加权图像,最后用两样本t检验分别比较两组患者及两组患者父母之间的脑灰质密度的差别。结果与散发性患者相比,家族性精神分裂症患者双侧丘脑的灰质密度均有降低。家族性分裂症患者父母的双侧丘脑、右侧海马旁回、左侧海马及左侧颞上回灰质密度较散发性患者父母降低。与正常对照相比,家族性及散发性精神分裂症患者双侧岛、右侧颞叶、右侧枕叶、左侧苍白球、右侧小脑及左侧额叶直回的灰质密度降低。两组患者的父母组中,只有家族性患者父母的一些脑区(包括右侧丘脑)的灰质密度较正常对照降低。结论家族性精神分裂症患者的双侧丘脑灰质密度较散发性患者显著降低,为以往研究中发现的家族性和散发性精神分裂症患者临床症状学的差异提供了脑结构的神经影像学证据。同时,家族性患者父母双侧丘脑的灰质密度较散发性患者父母也有明显降低,这一结果说明两组患者丘脑结构的差异与遗传有较大的关系。     

抑郁症患者脑MR血流灌注的图像特征

目的 利用动脉自旋标记法(ASL)探讨难治性与非难治性抑郁症的脑血流特征.方法 选择本院年龄、性别配对的门诊12例难治性抑郁症患者、37例非难治性抑郁症患者和42名健康志愿者,采用流动敏感交互反转恢复序列(FAIR)进行灌注成像.影像处理是将标记和未标记影像相减,然后平均得到灌注加权影像.将3组灌注加权影像采用基于像素分析方法(voxel based analysis,VBA)进行分析,统计采用ANOVA方差分析,并将年龄作为参变量.结果 非难治性抑郁症患者脑血流灌注变化的区域主要包括两个额叶一皮质通路,即灌注降低区域在左额叶和丘脑(边缘-丘脑-皮质通路),而灌注增加区域在双侧海马、右豆状核及左侧扣带回前部(边缘-纹状体-苍白球-丘脑通路).相比之下,难治性患者灌注降低区域主要涉及两侧额叶区(边缘-丘脑-皮质通路),而无灌注增加的区域.结论该研究揭示了抑郁症患者脑异常灌注区域,并利用ASL技术发现难治性与非难治性抑郁症患者存在不同的灌注异常区域.