精神分裂症患者全脑白质纤维弥散张量成像的初步研究

目的运用能够提示白质纤维(white matter,WM)完整性的弥散张量成像(diffusion tensor imaging,DTI)技术,探讨精神分裂症患者全脑白质纤维是否受到损害。方法对21例精神分裂症患者(患者组)和21名健康人(对照组)进行全脑DTI扫描,用SPM2(Statistical Parametric Maps,SPM)软件对图像进行处理,采用以像素为基础的分析方法(voxel-based analysis,VBA)对两组的分数各向异性(fractional anisotropy,FA)值进行组间比较。结果患者组下列脑区的FA值显著低于对照组(P<0·001):左侧额眶区和右侧额中回的白质、双侧颞下回白质、双侧顶叶内侧白质、右侧前扣带、双侧海马、双侧大脑脚、双侧岛叶、右侧放射冠和右侧小脑上脚。结论精神分裂症多个部位脑白质纤维的完整性受到破坏。     

老年抑郁症恢复期患者认知损害与全脑白质纤维完整性的相关性研究

目的 探讨恢复期老年抑郁症患者全脑白质纤维完整性是否受损,并进一步分析其与认知损害是否关联.方法 对16例恢复期老年抑郁症患者(患者组)和14名健康老年人(对照组)进行汉密尔顿抑郁量表(HAMD)、简易智力状态检查(MMSE)和神经心理学评估后,行全脑弥散张量成像扫描,用SPM2软件处理图像,采用基于体素的分析方法进行组间比较分数各向异性(FA)值.结果 (1)HAMD、MMSE评分和神经心理学测试:患者组HAMD和MMSE评分与正常对照组的差异无统计学意义(P>0.05),但在听觉言语测验[(5.9±2.6)分]、连线测验A[(146±127)s]和B[(264±196)s]成绩均差于正常对照组[分别为(9.3±1.6)分,(73±25)s和(121±35)s;P<0.01～0.05].(2)FA值:患者组低于对照组的脑区主要包括:右侧额上回、左侧额下回、左侧颞中回、右侧顶下回、右侧枕中回、左侧舌回、右侧壳核和右侧尾状核(未校正,P<0.001).(3)患者组右侧额上回FA值与连线B测验成绩呈显著负相关(r=-0.556,P=0.049).结论 恢复期老年抑郁症患者多部位脑白质纤维的完整性受损,这可能是该类患者认知损害的神经病理基础.     

重性抑郁症脑白质性别差异的初步研究

目的 利用磁共振弥散张量成像技术探讨重性抑郁症患者脑白质纤维是否存在性别差异.方法 24例重性抑郁症患者(男15例,女9例)及30名正常对照(男11名,女19名)均经常规核磁共振(MRI)和DTI扫描,基于像素的全脑分析技术对各组间DTI数据进行比较分析.结果 [1]男性患者左额中回、右颞叶回下、左梭状回、楔前叶及右顶叶回下等区域各向异性值(faraction anistropy, FA)低于男性正常对照(P<0.001);女性患者在右额上回、额叶回下、颞叶回下、左颞上回及右后扣带回等白质区域的FA值低于女性正常对照(P<0.001).[2]女性患者在右顶叶回下、左中央前回、右颞中回及右扣带回白质区域的FA值低于男性患者(P<0.001);女性正常对照仅在左边缘叶下回及左枕叶中回的区域的FA值低于男性正常对照(P<0.001).结论 男女抑郁症患者均存在脑白质异常区域,且两老少间存在差异.     

首、复发抑郁症患者额颞叶神经纤维偏侧化与疾病严重程度的相关研究

目的:探讨首、复发抑郁症患者额颞叶神经纤维是否存在偏侧化改变,以及与认知、疾病严重程度的相关性。方法:入组首发抑郁症患者25例、复发抑郁症患者27例及健康对照者24名,入组者均进行弥散张量成像扫描(DTI)及威斯康辛卡片分类测试(WCST);抑郁患者同时进行汉密尔顿抑郁量表(HAMD)评分。结果:首、复发抑郁组,在右额中回、右额下回、右颞下回的各向异性(FA)值较左侧显著性降低(P0.05),复发抑郁组右侧海马回FA值较左侧显著性升高(P0.01),健康对照组未发现左右脑FA值差异有统计学意义(P0.05);对照组左额叶中回、左额下回FA值与持续错误数正相关,右额下回FA值与完成第一分类所需应答数正相关,首发抑郁组的左额叶中回FA值与持续错误数相关,右额下回FA值与完成第一分类所需应答数相关(P均0.05);复发抑郁组右额下回FA值与HAMD评分呈负相关(P0.05)。结论:首、复发抑郁症患者均存在右侧颞叶、额叶的偏侧化,且与认知功能的改变存在一定的相关性,反复发作、病程迁延的复发患者偏侧化程度进一步加重,且右侧额叶下回的纤维完整性与疾病严重程度呈负相关。     

未经治疗的抑郁症首次发病患者脑弥散张量成像的研究

目的 通过对未经治疗的抑郁症首次发病(以下简称首发)患者进行弥散张最成像(DTI)检查,探讨抑郁症患者脑门质的完整性及其与病程和抑郁严重程度的相关性.方法 对17名首发末服药抑郁症患者(以下简称患者组)和17名年龄、性别和文化程度相匹配的健康对照(以下简称对照组)进行全脑DTI扫描.以基于体素的分析比较两组受试者脑白质的分数各向异性(FA)的差异.提取差异有统计学意义的脑区的FA绝对值,将其与汉密尔顿抑郁量表(17项,HAMD)总分和患者病程进行相关分析.结果 患者组的双侧额中回、左侧扣带回和颞下回白质的FA值显著低于对照组(P＜0.01,cluster＞100).右侧额中回的FA值与病程呈显著负相关(r=-0.732,P=0.001).未发现各脑区的FA值与HAMD总分存在相关.结论脑白质完整性异常可能是抑郁症的生物学特征之一,抑郁症病程对脑白质的完整性有明显影响.     

弥散张量成像对阿尔茨海默病脑白质改变的评价

目的分析阿尔茨海默病(Alzheimer's disease,AD)脑白质结构改变及与认知功能的关系。方法对37例AD组和32例对照组行简易精神状态量表(mini-mental State examinationn,MMSE)评估和DTI扫描。采用基于全脑体素分析法对两组全脑白质各向异性(fractional anisotropy,FA)图进行比较,采用t检验分析FA值差异,并评估AD组MMSE评分与FA值相关性。结果 AD患者出现FA值下降区域广泛分布在右侧额叶、颞叶、枕叶、丘脑及双侧扣带回、胼胝体、楔前叶、顶叶下回、顶下小叶、缘上回及海马旁回(其中P0.001,未经校正的P值);当使用经FWE校正的P0.05后,AD患者右侧扣带回、左侧胼胝体、颞叶下回及双侧顶叶下回、额叶下回、楔前叶区域FA值较对照组显著下降。AD患者FA值下降与MMSE量表评分呈正相关,(P0.001,未经校正)。结论 AD患者存在特定脑区白质结构改变,并与认知功能损害程度呈正相关。     

语义性痴呆结构性磁共振成像研究

目的分析语义性痴呆患者灰质和白质结构变化,提高对其病理改变和发生机制的认识。方法采用3.0T MRI扫描仪对16例语义性痴呆患者和17例正常对照者进行全脑扫描,扫描序列包括三维高分辨力结构像和扩散张量成像(DTI)。通过专业统计软件分别对全脑灰质密度和白质纤维束部分各向异性(FA)值进行分析,比较两组受试者全脑灰质密度(P0.001,Voxel338)和白质纤维束FA值(P0.005,Voxel103)。结果与对照组相比,语义性痴呆组患者双侧颞叶,特别是颞极表现为灰质密度显著降低,以左侧大脑半球额颞顶叶灰质密度减低区域更为广泛,包括左侧颞下回、缘上回、顶下回和额中回;同时双侧颞叶白质纤维束FA值显著降低,包括双侧钩束、左侧扣带(海马)纤维和双侧下额枕束。白质纤维束FA值分析结果与VBM法所显示的灰质密度在解剖学上呈现极高的一致性。结论本研究在体揭示了语义性痴呆的病理学和解剖学基础,为理解语义性痴呆的病理学机制提供了客观佐证。     

抑郁症患者脑白质变化初步研究

目的：利用能够提示脑白质纤维完整性的磁共振弥散张量成像（DTI）探讨首发和复发重性抑郁症患者脑白质纤维的变化及其差异。方法：20例重性抑郁症患者（首发9例，复发11例）和20名正常对照者均经常规磁共振成像（MRI）平扫，未发现异常者继续进行DTI和结构MRI（3D）扫描，基于像素的全脑分析技术对DTI数据进行分析。结果：与对照组相比较，抑郁症组白质纤维结构在双侧额中回、右顶下小叶及双侧脑岛等区域白质的各向异性值（FA）显著降低（各脑区P均〈0.001，cluster〉30像素）;与首发抑郁症患者相比较，复发抑郁症患者右侧额上回、右顶叶、中央前回、中央后回及右顶下小叶等区域FA值降低更为显著（各脑区P均〈0.001，cluster〉10像素）。结论：重性抑郁症患者存在脑白质异常，抑郁反复发作会导致脑白质损害进一步加重。     

精神分裂症患者及其健康同胞的弥散张量成像研究

目的 探索精神分裂症患者及其健康同胞是否存在类似的脑白质完整性异常.方法 采用弥散张量成像技术扫描精神分裂症患者(患者组)、患者的健康同胞(同胞组)和健康对照(对照组)的全脑,用基于体素的分析方法比较3组的白质纤维分数各向异性(fractional anisotropy,FA)值.结果 在左侧前额叶和海马区,患者组(左侧前额叶:0.303±0.006,海马:0.310±0.O05)和同胞组(左侧前额叶:0.320±0.006,海马:0.318±0.006)的白质FA值显著小于对照组(左侧前额叶:0.338±0.007,海马:0.338±0.005),差异均有统计学意义(P＜0.05),患者组与同胞组的差异无统计学意义(P＞0.05);在左侧前扣带区,患者组白质FA值(0.391±0.006)显著小于同胞组(0.423±0.006)和对照组(0.412±0.007),差异有统计学意义(P＜0.05),同胞组的FA值大于对照组,但差异无统计学意义(P＞0.05).结论 精神分裂症患者及其健康同胞存在相似的脑白质完整性异常,左侧前额叶和海马白质FA值降低可能意味着精神分裂症的患病风险,左侧前扣带的白质FA值降低则可能是向该病转换的决定因素.     

轻度认知损害脑白质病变的扩散张量成像研究

目的 通过扩散张量成像(DTI)和基于体素的分析方法进行全脑部分各向异性(FA)差异性分析,尝试发现遗忘型轻度认知损害(aMCI)患者脑白质的特征性改变.方法 根据遗忘型轻度认知损害诊断标准和单项神经心理学测验(词表记忆、相似性、领悟力、连线A、图形自由回忆等),16例遗忘型轻度认知损害患者接受头部DTI,所得影像资料行基于体素的分析.并与认知功能正常者(对照组)比较全脑FA值差异性.结果 (1)对照组简易智能状态检查量表总评分为28.69±1.03,高于aMCI组的27.50 ±1.65(t=1.278.P=0.035).(2)对照组蒙特利尔认知评价量表总评分为25.85±1.52,高于aMCI组的22.50±1.91(t=0.900,P=0.000).(3)对照组词语流畅性词汇数目为(19.08±4.92)个,多于aMCI组的(15.14±4.66)个(t=0.012,P=0.043).(4)对照组词表记忆、延迟词表回忆、词语辨认、图形自由回忆测验评分分别为5.544±0.88、5.15±1.77、9.15±1.07和14.69±2.25,高于aMCI组的3.984±1.07、2.14±1.23、7.00±2.04和10.574±2.31(均P=0.000).(5)aMCI组左侧额中回、右侧额中回白质区FA值显著低于对照组,差异有统计学意义(均P<0.001).结论 额叶白质病变可能参与遗忘型轻度认知损害的早期病理生理学过程.     

基于体素的形态测量法分析高功能孤独性障碍患儿的脑组织密度

目的 分析学龄孤独性障碍患儿脑组织密度.方法 对17例智能正常的孤独性障碍患儿(病例组)以及15名年龄、性别、智商与之相匹配的健康儿童(对照组)进行T1加权三维磁共振成像扫描,应用基于体素的形态测量法(VBM)比较两组脑灰质及脑白质密度的差异.结果 与对照组相比,孤独性障碍患儿右侧小脑前叶的脑灰质密度低.右前扣带回、右额中回区域的脑白质密度低,双侧顶下小叶、右缘上回、右中央后回、右颞上回、右小脑后叶、左楔前叶、左楔叶的脑灰质密度高(P<0.001).结论 智力正常的学龄孤独性障碍患儿脑组织密度异常明显,且部位广泛.     

Voxel-based analyses of gray/white matter volume and diffusion tensor data in major depression

The purpose of this study is to use voxel-based analysis to simultaneously elucidate regional changes in gray/white matter volume, mean diffusivity (MD), and fractional anisotropy (FA) in patients with unipolar major depressive disorder. We studied 21 right-handed patients and 42 age- and gender-matched right-handed normal subjects. Local areas showing significant gray matter volume reduction in depressive patients compared with controls were observed in the right parahippocampal gyrus, hippocampus, bilateral middle frontal gyri, bilateral anterior cingulate cortices, left parietal and occipital lobes, and right superior temporal gyrus. Local areas showing an increase of MD in depressive patients were observed in the bilateral parahippocampal gyri, hippocampus, pons, cerebellum, left frontal and temporal lobes, and right frontal lobe. There was no significant difference between the two groups for FA and white matter volume in the entire brain. Although there was no local area where brain volume and MD were significantly correlated with disease severity, FA tended to correlate negatively with total days depressed in the right anterior cingulate and the left frontal white matter. These results suggest that the frontolimbic neural circuit might play an important role in the neuropathology of patients with major depressive disorder.     

弥散张量成像在继发全面性发作癫痫患者中的应用研究

目的 评价弥散张量成像(DTI)对于常规MRI未发现病灶的部分性继发全面性发作癫痫患者的病灶检出能力.方法 使用Siemens 3.0T磁共振成像系统对30例成年继发全面性发作癫痫患者和30例正常对照者进行扫描,得到弥散加权成像,采用基于体素的分析方法对癫痫患者和正常对照组的数据进行分析.结果 癫痫组右侧梭状回和楔前叶、右侧额内侧回和钩回、左侧扣带回、左侧颞下回、左侧小脑扁桃体和左侧中央前回的脑区FA值较正常对照组降低,差异有统计学意义(P＜0.001);癫痫组右侧海马旁回、右侧颞下回、右侧胼胝体、右侧额内侧回、右侧额下回、扣带回、右侧前扣带回、右侧舌回、右侧梭状回和枕中回,左侧颞中回、左侧钩回和左侧中央前回的脑区ADC值较正常对照组升高,差异具有统计学意义(P＜0.001);左侧直回的脑区ADC值较正常对照组降低,差异具有统计学意义(P＜0.001).结论 DTI检查可发现常规MRI检查为阴性的部分性继发全面性发作癫痫患者存在的广泛脑白质微结构异常.     

Functional and anatomical connectivity abnormalities in left inferior frontal gyrus in schizophrenia

Functional studies in schizophrenia demonstrate prominent abnormalities within the left inferior frontal gyrus (IFG) and also suggest the functional connectivity abnormalities in language network including left IFG and superior temporal gyrus during semantic processing. White matter connections between regions involved in the semantic network have also been indicated in schizophrenia. However, an association between functional and anatomical connectivity disruptions within the semantic network in schizophrenia has not been established. Functional (using levels of processing paradigm) as well as diffusion tensor imaging data from 10 controls and 10 chronic schizophrenics were acquired and analyzed. First, semantic encoding specific activation was estimated, showing decreased activation within the left IFG in schizophrenia. Second, functional time series were extracted from this area, and left IFG specific functional connectivity maps were produced for each subject. In an independent analysis, tract‐based spatial statistics (TBSS) was used to compare fractional anisotropy (FA) values between groups, and to correlate these values with functional connectivity maps. Schizophrenia patients showed weaker functional connectivity within the language network that includes left IFG and left superior temporal sulcus/middle temporal gyrus. FA was reduced in several white matter regions including left inferior frontal and left internal capsule. Finally, left inferior frontal white matter FA was positively correlated with connectivity measures of the semantic network in schizophrenics, but not in controls. Our results indicate an association between anatomical and functional connectivity abnormalities within the semantic network in schizophrenia, suggesting further that the functional abnormalities observed in this disorder might be directly related to white matter disruptions. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.     

Voxel-based morphometry study on brain structure in children with high-functioning autism

Earlier studies have suggested abnormal brain volumes in autism, but inconsistencies exist. Using voxel-based morphometry, we compared global and regional brain volumes in 17 high-functioning autistic children with 15 matched controls. We identified significant reduction in left white matter volume and white/gray matter ratio in autism. Regional brain volume reductions were detected for right anterior cingulate, left superior parietal lobule white matter volumes, and right parahippocampal gyrus gray matter volume, whereas enlargements in bilateral supramarginal gyrus, right postcentral gyrus, right medial frontal gyrus, and right posterior lobe of cerebellum gray matter in autism. Our findings showed global and regional brain volumes abnormality in high-functioning autism.