BACKGROUND： Previous studies regarding primary progressive aphasia （PPA） have focused on progressive, non-fluent aphasia. Little information is available with regard to the use of diffusion tensor imaging compared ...BACKGROUND： Previous studies regarding primary progressive aphasia （PPA） have focused on progressive, non-fluent aphasia. Little information is available with regard to the use of diffusion tensor imaging compared with conventional magnetic resonance imaging for the detection of subtle structural abnormalities. OBJECTIVE： To investigate and localize brain abnormalities in a Chinese patient with semantic dementia. DESIGN, TIME AND SETTING： A concurrent, non-randomized, case-controlled, neuroimaging, clinical trial was performed at the Department of Radiology, West China Hospital of Sichuan University in March 2009. PARTICIPANTS： One 75-year-old male patient, who was diagnosed with semantic dementia, and 21 age- and gender-matched healthy volunteers were recruited for the study. METHODS： Diffusion tensor imaging was used to determine mean diffusion （MD） and fractional anisotropy （FA） in the brains of the patient and the 21 healthy subjects. Voxel-based analysis of MD and FA values was performed using statistical parametric mapping. MAIN OUTCOME MEASURES： MD and FA value maps differences between patient and controls. RESULTS： MD was significantly increased in both cerebra, but was predominant on the left side and expanded to outside of the language-related region. Reduced MD was not detected in any of the brains. FA was shown to be decreased in the corpus callosum, but was increased in the basal ganglia. CONCLUSION： The present study provided clear in vivo magnetic imaging evidence of diffuse brain involvement in semantic dementia. Increases in MD were greater than in FA when brain diffusion alterations were detected, which suggested that MD could be a better marker of disease progression.展开更多
Objective To study the microscopic changes of white matter and the relationship between white matter changes and cognitive impairment in Alzheimer’s disease(AD)using voxel-based analysis of DTI.Methods Thirty-seven p...Objective To study the microscopic changes of white matter and the relationship between white matter changes and cognitive impairment in Alzheimer’s disease(AD)using voxel-based analysis of DTI.Methods Thirty-seven patients with probable AD,and 32 normal controls(NC)were all examined by MMSE scores,and un-展开更多
Schizophrenia is considered to be a disorder of brain connectivity, which might result from a disproportionally impaired rich-club organization. The rich-club is composed of highly interconnected hub regions that play...Schizophrenia is considered to be a disorder of brain connectivity, which might result from a disproportionally impaired rich-club organization. The rich-club is composed of highly interconnected hub regions that play crucial roles in integrating information between different brain regions. Few studies have yet investigated whether the structural rich-club organization is impaired in patients and their first-degree relatives. In this study, we established a weighted network model of white matter connections using diffusion tensor imaging of 19 patients and 39 unaffected parents, 22 young healthy controls for the patients, and 25 old healthy controls for the parents. Feeder edges between rich-club nodes and non-rich-club nodes were significantly decreased in both schizophrenic patients and their unaffected parents compared with controls.Furthermore, the feeder edges showed significant positive correlations with the scores in Category Fluency Test—animal naming in the unaffected parents. Specific feeder edges exhibited discriminative power with accuracy of 84.4% in distinguishing unaffected parents from old healthy controls. Our findings suggest that impaired richclub organization, especially impaired feeder edges, may be related to familial vulnerability to schizophrenia,possibly reflecting a genetic predisposition for schizophrenia.展开更多
BACKGROUND Major depressive disorder(MDD)in adolescents and young adults contributes significantly to global morbidity,with inconsistent findings on brain structural changes from structural magnetic resonance imaging ...BACKGROUND Major depressive disorder(MDD)in adolescents and young adults contributes significantly to global morbidity,with inconsistent findings on brain structural changes from structural magnetic resonance imaging studies.Activation likeli-hood estimation(ALE)offers a method to synthesize these diverse findings and identify consistent brain anomalies.METHODS We performed a comprehensive literature search in PubMed,Web of Science,Embase,and Chinese National Knowledge Infrastructure databases for neuroi-maging studies on MDD among adolescents and young adults published up to November 19,2023.Two independent researchers performed the study selection,quality assessment,and data extraction.The ALE technique was employed to synthesize findings on localized brain function anomalies in MDD patients,which was supplemented by sensitivity analyses.RESULTS Twenty-two studies comprising fourteen diffusion tensor imaging(DTI)studies and eight voxel-based morphome-try(VBM)studies,and involving 451 MDD patients and 465 healthy controls(HCs)for DTI and 664 MDD patients and 946 HCs for VBM,were included.DTI-based ALE demonstrated significant reductions in fractional anisotropy(FA)values in the right caudate head,right insula,and right lentiform nucleus putamen in adolescents and young adults with MDD compared to HCs,with no regions exhibiting increased FA values.VBM-based ALE did not demonstrate significant alterations in gray matter volume.Sensitivity analyses highlighted consistent findings in the right caudate head(11 of 14 analyses),right insula(10 of 14 analyses),and right lentiform nucleus putamen(11 of 14 analyses).CONCLUSION Structural alterations in the right caudate head,right insula,and right lentiform nucleus putamen in young MDD patients may contribute to its recurrent nature,offering insights for targeted therapies.展开更多
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 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.展开更多
文摘BACKGROUND： Previous studies regarding primary progressive aphasia （PPA） have focused on progressive, non-fluent aphasia. Little information is available with regard to the use of diffusion tensor imaging compared with conventional magnetic resonance imaging for the detection of subtle structural abnormalities. OBJECTIVE： To investigate and localize brain abnormalities in a Chinese patient with semantic dementia. DESIGN, TIME AND SETTING： A concurrent, non-randomized, case-controlled, neuroimaging, clinical trial was performed at the Department of Radiology, West China Hospital of Sichuan University in March 2009. PARTICIPANTS： One 75-year-old male patient, who was diagnosed with semantic dementia, and 21 age- and gender-matched healthy volunteers were recruited for the study. METHODS： Diffusion tensor imaging was used to determine mean diffusion （MD） and fractional anisotropy （FA） in the brains of the patient and the 21 healthy subjects. Voxel-based analysis of MD and FA values was performed using statistical parametric mapping. MAIN OUTCOME MEASURES： MD and FA value maps differences between patient and controls. RESULTS： MD was significantly increased in both cerebra, but was predominant on the left side and expanded to outside of the language-related region. Reduced MD was not detected in any of the brains. FA was shown to be decreased in the corpus callosum, but was increased in the basal ganglia. CONCLUSION： The present study provided clear in vivo magnetic imaging evidence of diffuse brain involvement in semantic dementia. Increases in MD were greater than in FA when brain diffusion alterations were detected, which suggested that MD could be a better marker of disease progression.
文摘Objective To study the microscopic changes of white matter and the relationship between white matter changes and cognitive impairment in Alzheimer’s disease(AD)using voxel-based analysis of DTI.Methods Thirty-seven patients with probable AD,and 32 normal controls(NC)were all examined by MMSE scores,and un-
基金supported by grants from the National Basic Research Program of China(2011CB707805)the National Natural Science Foundation of China(81370032,91232305,81361120395,and 91432304)the International Science and Technology Cooperation Program of China(2010DFB30820)
文摘Schizophrenia is considered to be a disorder of brain connectivity, which might result from a disproportionally impaired rich-club organization. The rich-club is composed of highly interconnected hub regions that play crucial roles in integrating information between different brain regions. Few studies have yet investigated whether the structural rich-club organization is impaired in patients and their first-degree relatives. In this study, we established a weighted network model of white matter connections using diffusion tensor imaging of 19 patients and 39 unaffected parents, 22 young healthy controls for the patients, and 25 old healthy controls for the parents. Feeder edges between rich-club nodes and non-rich-club nodes were significantly decreased in both schizophrenic patients and their unaffected parents compared with controls.Furthermore, the feeder edges showed significant positive correlations with the scores in Category Fluency Test—animal naming in the unaffected parents. Specific feeder edges exhibited discriminative power with accuracy of 84.4% in distinguishing unaffected parents from old healthy controls. Our findings suggest that impaired richclub organization, especially impaired feeder edges, may be related to familial vulnerability to schizophrenia,possibly reflecting a genetic predisposition for schizophrenia.
基金Supported by the Guizhou Province Science and Technology Plan Project,No.ZK-2023-1952021 Health Commission of Guizhou Province Project,No.gzwkj2021-150.
文摘BACKGROUND Major depressive disorder(MDD)in adolescents and young adults contributes significantly to global morbidity,with inconsistent findings on brain structural changes from structural magnetic resonance imaging studies.Activation likeli-hood estimation(ALE)offers a method to synthesize these diverse findings and identify consistent brain anomalies.METHODS We performed a comprehensive literature search in PubMed,Web of Science,Embase,and Chinese National Knowledge Infrastructure databases for neuroi-maging studies on MDD among adolescents and young adults published up to November 19,2023.Two independent researchers performed the study selection,quality assessment,and data extraction.The ALE technique was employed to synthesize findings on localized brain function anomalies in MDD patients,which was supplemented by sensitivity analyses.RESULTS Twenty-two studies comprising fourteen diffusion tensor imaging(DTI)studies and eight voxel-based morphome-try(VBM)studies,and involving 451 MDD patients and 465 healthy controls(HCs)for DTI and 664 MDD patients and 946 HCs for VBM,were included.DTI-based ALE demonstrated significant reductions in fractional anisotropy(FA)values in the right caudate head,right insula,and right lentiform nucleus putamen in adolescents and young adults with MDD compared to HCs,with no regions exhibiting increased FA values.VBM-based ALE did not demonstrate significant alterations in gray matter volume.Sensitivity analyses highlighted consistent findings in the right caudate head(11 of 14 analyses),right insula(10 of 14 analyses),and right lentiform nucleus putamen(11 of 14 analyses).CONCLUSION Structural alterations in the right caudate head,right insula,and right lentiform nucleus putamen in young MDD patients may contribute to its recurrent nature,offering insights for targeted therapies.
基金supported by the Project of Science and Technology Department of Jilin Province in China,No.20160101023JC
文摘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.
文摘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(P<0.05)。患者组额叶左右侧FA值差异无统计学意义(P>0.05),而对照组左侧大于右侧(P<0.05);患者组内囊膝部和后肢FA值右侧大于左侧(P<0.05),而对照组左侧大于右侧(P<0.05)。患者组双侧外囊FA值均小于对照组(P<0.05)。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。
