高功能孤独症患儿全脑白质纤维的弥散张量成像研究

目的 分析高功能孤独症患儿的全脑白质纤维的完整性.方法 对18例高功能孤独症患儿(病例组)以及10名年龄、性别、智商与病例组相匹配的健康儿童(对照组)进行全脑弥散张量成像(DTI)测量;应用基于体素的分析方法,比较两组全脑各向异性分数(FA)的差异.使用Spearman相关分析,分析病例组各感兴趣区FA值与儿章期孤独症评定表(CARS)总分及各项目之间的关系.结果 与对照组相比,病例组右侧额下回、左侧额中回及右侧颞下回邻近白质的FA值低(分别为0.67±0.10、0.57±0.09、0.50 ±0.12),左顶上小叶邻近白质的FA值高(0.55±0.15;P<0.001).病例组左额中回邻近白质的FA值与CARS中的与非生命物体的关系的得分呈负相关(r=-0.63,P=0.005).结论 高功能孤独症患儿多个部位的脑白质纤维的完整性受到破坏.     

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.     

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。     

首发未服药精神分裂症患者脑弥散张量成像的基于体素分析

目的分析首发未服药精神分裂症患者脑白质完整性的变化。 方法对40例首发未服药精神分裂症患者和68例健康对照者进行脑弥散张量磁共振成像检查,以DTI-studio软件和统计参数图(SPM)软件对所得图像进行预处理,得到的各向异性分数(FA)图像在SPM软件中进行两样本t检验,获得两组患者FA值差异统计参数图。 结果在P值小于0.001（未校正）水平下,首发未服药精神分裂症患者右侧杏仁核区(MNI：24,2,-14,cluster=347 voxels)、双侧前扣带区(MNI:6,42,2,cluster=586 voxels)、右侧前额叶眶上回区域(MNI：20,18,-10,cluster= 166 voxels)白质FA值较健康对照者下降,且未发现前者有脑区白质FA值较后者增高。 结论精神分裂症患者皮层一边缘系统环路存在结构连接障碍,这可能是精神分裂症的神经机制。     

首发偏执型精神分裂症患者的脑白质磁共振弥散张量成像研究

目的探讨首发未用药的偏执型精神分裂症患者的多个脑区白质磁共振弥散张量成像(diffusion tensor imaging,DTI)的特点,以期为精神分裂症"脑内连接异常的假说"提供依据。方法选取20例首发偏执型精神分裂症患者,应用DTI扫描,检测脑内21个感兴趣区(regions of interest,ROI)白质纤维的微细结构,并与20名年龄、性别和文化程度相匹配的正常对照比较。结果患者组额叶、内囊前肢、外囊的左右两侧FA值和左侧颞叶、左侧内囊膝部、胼胝体膝部FA值小于对照组(P0.05)。患者组额叶左右侧FA值差异无统计学意义(P0.05),而对照组左侧大于右侧(P0.05);患者组内囊膝部和后肢FA值右侧大于左侧(P0.05),而对照组左侧大于右侧(P0.05)。患者组双侧外囊FA值均小于对照组(P0.05)。结论未用药首发偏执型精神分裂症患者脑内多个白质区部分各向异性降低,尤其是额叶皮层下环路更加显著,数个白质区部分各向异性的正常"左右"的偏侧性缺失或倒置,支持精神分裂症脑内连接异常的神经病理假说。     

慢性偏头痛患者脑白质弥散张量成像ABA及TBSS分析

目的采用弥散张量成像(DTI)技术研究慢性偏头痛(CM)患者脑白质结构损伤及其与临床资料的相关性。方法选取成都中医药大学附属医院神经内科、神经外科门诊自2020年9月至2022年12月收治的CM患者60例(CM组), 自2020年10月至2022年6月向社会招募与CM患者年龄、性别相匹配的健康对照者60例(健康对照组)。2组受试者均进行全脑DTI扫描, 使用PANDA及FSL软件进行DTI数据全自动处理, 采用基于白质图谱的分析(ABA)及纤维束示踪空间统计(TBSS)分析CM患者及健康对照者全脑DTI数据的差异, 采用Pearson相关性检验分析CM患者临床特征与ABA结果的相关性。结果 ABA结果显示:与健康对照组比较, CM组患者双侧大脑脚、左侧小脑下脚、右侧小脑上脚、双侧内侧丘系、双侧毯(胼胝体内矢状层)、双侧钩束及右侧内囊后肢脑区的各向异性分数(FA)值降低, 右侧扣带回、内囊豆状核后部脑区的平均弥散率(MD)值增高, 双侧大脑脚、双侧内侧丘系、右侧扣带回脑区轴向弥散率(AD)值降低, 左侧毯(胼胝体内矢状层)、左侧小脑下脚、左侧大脑脚脑区径向弥散率(RD)值增高, 差异均有...     

精神分裂症首次发病患者的脑扩散张量成像研究

目的 利用磁共振扩散张量成像(DTI)技术研究未经药物治疗的精神分裂症首次发病(以下简称首发)患者主要脑区白质纤维束的异常.方法 选取26例首发精神分裂症患者(患者组)和20名健康志愿者(对照组)行脑DTI扫描(两组均为右利手),测量胼胝体膝部、压部、双侧额叶白质、扣带束前部及海马头的部分各向异性(FA)值.结果 (1)对照组左侧扣带束FA值(0.428±0.067)大于右侧(0.375±0.079;P＜0.05).(2)患者组两侧相对应感兴趣区FA值差异均无统计学意义(P＞0.05).(3)患者组左右侧胼胝体压部FA值(均为0.734±0.085)、左右侧扣带束前部FA值(0.300±0.068和0.306 4±0.062)均低于对照组(0.785±0.045,0.428±0.067,0.375±0.079;均P＜0.05).结论 首发精神分裂症患者存在双侧扣带束、胼胝体压部白质纤维束的受损,支持脑内连接异常假说.     

女性重性抑郁障碍患者体质量指数与脑白质完整性异常的相关性研究

目的:探讨女性重性抑郁障碍患者体质量指数(BMI)与脑白质完整性异常的相关性。方法:收集自2017年10月至2018年10月门诊就诊的女性重性抑郁障碍患者58例(患者组)及年龄、BMI、受教育程度相匹配的女性健康对照者57名(对照组)进行核磁共振扫描,完成临床相关量表的评定。比较两组磁共振弥散张量成像(DTI)数据,分别对两组的DTI图像与BMI进行相关性分析,并对各向异性值(FA值)进行提值计算。结果:患者组与对照组DTI比较存在两簇差异脑区,分别位于胼胝体压部及体部、右下额枕束,且患者组的FA值低于对照组。患者组BMI与右侧外囊的FA值呈正相关(r=0.531,P0.01);对照组BMI与胼胝体体部、膝部及压部的FA值呈负相关(r=-0.497,P0.01)。结论:女性重性抑郁障碍患者胼胝体压部、体部及右下额枕束白质完整性降低,肥胖所致的胼胝体完整性降低可能是重性抑郁障碍患者患病的相关因素。     

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.     

首发精神分裂症阳性症状为主型患者脑弥散张量成像研究

目的 探讨首发精神分裂症阳性症状为主型患者主要脑区白质纤维束有无异常.方法 对未系统使用过精神药物治疗的20例首发精神分裂症阳性症状为主型患者和20名正常对照进行磁共振弥散张量成像(DTI)扫描,测量胼胝体膝部、压部、双侧额叶白质、双侧扣带束前部和双侧海马头部分各向异性(FA)值.结果 ①患者组及对照组组内比较,左右侧FA值差异均无统计学意义(P>0.05).②患者组左侧海马头和胼胝体压部FA值[(0.17±0.03),(0.73±0.09)]显著低于对照组[(0.20±0.02),(0.79±0.05)],差异均有统计学意义(P<0.05);③患者组左右侧扣带束前部FA值[(0.28±0.06),(0.29±0.05)]低于对照组[(0.43±0.07),(0.38±0.08)],差异均有统计学意义(P<0.01).结论 首发精神分裂症阳性症状为主型患者双侧扣带束前部、胼胝体压部及左侧海马头的白质纤维束完整性受损,提示其可能存在脑神经发育连接异常.     

White matter integrity of the whole brain is disrupted in first-episode schizophrenia

Diffusion tensor imaging studies in schizophrenia have demonstrated lower diffusion anisotropy within white matter that provides information about brain white matter integrity. We have examined whether white matter is abnormal in first-episode schizophrenia by using diffusion tensor imaging. Twenty-one schizophrenic patients and healthy controls underwent diffusion tensor imaging scans that analyzed by using a rigorous voxel-based approach. We found that fractional anisotropy in white matter of the patients was lower than that in controls at the cerebral peduncle, frontal regions, inferior temporal gyrus, medial parietal lobes, hippocampal gyrus, insula, right anterior cingulum bundle and right corona radiata. These results suggested that white matter integrity of the whole brain was disrupted in early illness onset of schizophrenia.     

White matter integrity of the whole brain is disrupted in first-episode remitted geriatric depression

Previous studies have demonstrated lower-diffusion anisotropy within white matter in late-onset depression measured by diffusion tensor imaging, which provides information about brain white matter integrity. We have examined whether white matter is abnormal in first-episode remitted geriatric depression by using diffusion tensor imaging. Sixteen remitted geriatric depression patients and 14 well matched healthy controls underwent diffusion tensor-imaging scans of magnetic resonance imaging, which were analyzed by a rigorous voxel-based approach. We found that fractional anisotropy in white matter was lower in patients than in controls at the right superior frontal gyrus, left inferior frontal gyrus, left middle temporal gyrus, right inferior parietal lobule, right middle occipital gyrus, left lingual gyrus, right putamen and right caudate. These results suggested that the white matter integrity of the whole brain was disrupted in first-episode remitted geriatric depression, and that these abnormalities were perhaps involved in the psychopathology and pathophysiology of cognitive impairment in remitted geriatric depression.     

White matter abnormalities in first-episode schizophrenia or schizoaffective disorder: a diffusion tensor imaging study

OBJECTIVE: The goal of this study was to investigate brain white matter abnormalities by using diffusion tensor imaging in patients with schizophrenia or schizoaffective disorder close to illness onset. METHOD: Ten patients experiencing a first episode of schizophrenia or schizoaffective disorder and 13 healthy volunteers received diffusion tensor imaging and structural magnetic resonance imaging examinations. Voxel-wise analysis was used to compare fractional anisotropy maps in the white matter of the two groups following intersubject registration to Talairach space. RESULTS: Compared with healthy volunteers, patients demonstrated lower fractional anisotropy in the left internal capsule and left-hemisphere white matter of the middle frontal gyrus and posterior superior temporal gyrus. There were no areas of significantly higher fractional anisotropy in patients compared with healthy volunteers. CONCLUSIONS: These findings suggest that white matter pathology is present early in the course of schizophrenia and may be less pronounced than has been found in previous diffusion tensor imaging studies of patients with chronic illness. Further, these data are consistent with hypotheses regarding frontotemporal dysfunction and the failure of left-hemisphere lateralization in the pathophysiology of schizophrenia.     

White matter abnormalities in first-episode, treatment-naive young adults with major depressive disorder

OBJECTIVE: The aim of this study was to explore the microstructural integrity of whole-brain white matter by diffusion tensor imaging in first-episode, treatment-naive young adults with major depressive disorder. METHOD: Diffusion tensor imaging scans were obtained from 14 first-episode, treatment-naive young adult patients with major depressive disorder and 14 healthy comparison subjects. A voxel-based method was used to analyze the scans. RESULTS: The patient group exhibited significantly lower fractional anisotropy values than healthy comparison subjects in the white matter of the right middle frontal gyrus, the left lateral occipitotemporal gyrus, and the subgyral and angular gyri of the right parietal lobe. There were no regions of significantly higher fractional anisotropy values in patients compared with healthy comparison subjects. CONCLUSIONS: These findings suggest that abnormalities of brain white matter may be present early in the course of major depressive disorder. They also support the idea that white matter lesions may disrupt the neural circuits involved in mood regulation and thus contribute to the neuropathology of major depressive disorder.     

White matter microstructural abnormalities in late-life depression

OBJECTIVE: To evaluate the location and the degree of white matter damage in late-life depression using diffusion tensor imaging (DTI). METHODS: Thirty-one patients with late-life depression and 15 healthy volunteers matched for age, gender and years of education received conventional MRI (magnetic resonance imaging) and MR-diffusion tensor scanning. The fractional anisotropy (FA) values of white matter were measured respectively in frontal and temporal regions and the corpus callosum. RESULTS: FA values were significantly decreased in the frontal (superior and middle frontal gyrus), and temporal (right parahippocampal gyrus) regions of elderly patients with depression compared with healthy controls. CONCLUSION: Microstructural changes in the frontal (superior and middle frontal gyrus) and temporal (right parahippocampal gyrus) areas are associated with late-life depression.     

Correlation between white matter damage and gray matter lesions in multiple sclerosis patients

We observed the characteristics of white matter fibers and gray matter in multiple sclerosis patients, to identify changes in diffusion tensor imaging fractional anisotropy values following white matter fiber injury. We analyzed the correlation between fractional anisotropy values and changes in whole-brain gray matter volume. The participants included 20 patients with relapsing-remitting multiple sclerosis and 20 healthy volunteers as controls. All subjects underwent head magnetic resonance imaging and diffusion tensor imaging. Our results revealed that fractional anisotropy values decreased and gray matter volumes were reduced in the genu and splenium of corpus callosum, left anterior thalamic radiation, hippocampus, uncinate fasciculus, right corticospinal tract, bilateral cingulate gyri, and inferior longitudinal fasciculus in multiple sclerosis patients. Gray matter volumes were significantly different between the two groups in the right frontal lobe(superior frontal, middle frontal, precentral, and orbital gyri), right parietal lobe(postcentral and inferior parietal gyri), right temporal lobe(caudate nucleus), right occipital lobe(middle occipital gyrus), right insula, right parahippocampal gyrus, and left cingulate gyrus. The voxel sizes of atrophic gray matter positively correlated with fractional anisotropy values in white matter association fibers in the patient group. These findings suggest that white matter fiber bundles are extensively injured in multiple sclerosis patients. The main areas of gray matter atrophy in multiple sclerosis are the frontal lobe, parietal lobe, caudate nucleus, parahippocampal gyrus, and cingulate gyrus. Gray matter atrophy is strongly associated with white matter injury in multiple sclerosis patients, particularly with injury to association fibers.     

Voxelwise correlational analyses of white matter integrity in multiple cognitive domains in schizophrenia

Patients with schizophrenia show deficits in several neurocognitive domains. However, the relationship between white matter integrity and performance in these domains is poorly understood. The authors conducted neurocognitive testing and diffusion tensor imaging in 25 patients with schizophrenia. Performance was examined for tests of verbal declarative memory, attention, and executive function. Relationships between fractional anisotropy and cognitive performance were examined by using voxelwise correlational analyses. In each case, better performance on these tasks was associated with higher levels of fractional anisotropy in task-relevant regions.     

Increased regional fractional anisotropy in highly screened attention-deficit hyperactivity disorder (ADHD)

Diffusion tensor imaging data were collected at 3.0 Tesla from 16 children with attention-deficit hyperactivity disorder (ADHD) and 16 typically developing controls, ages 9 to 14 years. Fractional anisotropy images were calculated and normalized by linear transformation. Voxel-wise and atlas-based region-of-interest analyses were performed. Using voxel-wise analysis, fractional anisotropy was found to be significantly increased in the attention-deficit hyperactivity disorder group in the right superior frontal gyrus and posterior thalamic radiation, and left dorsal posterior cingulate gyrus, lingual gyrus, and parahippocampal gyrus. No regions showed significantly decreased fractional anisotropy in attention-deficit hyperactivity disorder. Region-of-interest analysis revealed increased fractional anisotropy in the left sagittal stratum, that is, white matter that connects the temporal lobe to distant cortical regions. Only fractional anisotropy in the left sagittal stratum was significantly associated with attention-deficit hyperactivity disorder symptom severity. Several recent studies have reported pathological increases in fractional anisotropy in other conditions, highlighting the relevance of diffusion tensor imaging in identifying atypical white matter structure associated with neurodevelopmental processes.     

Uncinate fasciculus findings in schizophrenia: a magnetic resonance diffusion tensor imaging study

OBJECTIVE: Disruptions in connectivity between the frontal and temporal lobes may explain some of the symptoms observed in schizophrenia. Conventional magnetic resonance imaging (MRI) studies, however, have not shown compelling evidence for white matter abnormalities, because white matter fiber tracts cannot be visualized by conventional MRI. Diffusion tensor imaging is a relatively new technique that can detect subtle white matter abnormalities in vivo by assessing the degree to which directionally organized fibers have lost their normal integrity. The first three diffusion tensor imaging studies in schizophrenia showed lower anisotropic diffusion, relative to comparison subjects, in whole-brain white matter, prefrontal and temporal white matter, and the corpus callosum, respectively. Here the authors focus on fiber tracts forming temporal-frontal connections. METHOD: Anisotropic diffusion was assessed in the uncinate fasciculus, the most prominent white matter tract connecting temporal and frontal brain regions, in 15 patients with chronic schizophrenia and 18 normal comparison subjects. A 1.5-T GE Echospeed system was used to acquire 4-mm-thick coronal line-scan diffusion tensor images. Maps of the fractional anisotropy were generated to quantify the water diffusion within the uncinate fasciculus. RESULTS: Findings revealed a group-by-side interaction for fractional anisotropy and for uncinate fasciculus area, derived from automatic segmentation. The patients with schizophrenia showed a lack of normal left-greater-than-right asymmetry seen in the comparison subjects. CONCLUSIONS: These findings demonstrate the importance of investigating white matter tracts in vivo in schizophrenia and support the hypothesis of a disruption in the normal pattern of connectivity between temporal and frontal brain regions in schizophrenia.     

White matter abnormalities in early-onset schizophrenia: a voxel-based diffusion tensor imaging study

OBJECTIVE: To investigate abnormalities in the structural integrity of brain white matter as suggested by diffusion tensor imaging in adolescents with early-onset schizophrenia (onset of psychosis by age 18). METHOD: Twenty-six patients with schizophrenia and 34 age- and gender-matched healthy volunteers received diffusion tensor imaging and structural magnetic resonance imaging examinations. Fractional anisotropy maps were compared between groups in the white matter using a voxelwise analysis after intersubject registration to Talairach space. RESULTS: Compared with healthy volunteers, patients demonstrated lower fractional anisotropy values in the left anterior cingulate region in close proximity to the caudate nucleus (95% confidence interval of schizophrenic-healthy: -66 to -20). Using regression analysis, the rate of change in fractional anisotropy differed significantly between groups in this region across the age span examined (10-20 years), after adjusting for group differences in premorbid intellectual capacity and parental socioeconomic status. There were no areas of significantly higher fractional anisotropy in patients compared with healthy volunteers. CONCLUSIONS: These data suggest that early-onset schizophrenia is associated with a disruption in the structural integrity of white matter tracts in the anterior cingulate region. These structural abnormalities may contribute to the deficits in motivation, attention, memory, and higher executive functions in adolescents with schizophrenia.