The purpose of this work was to demonstrate the feasibility of neurite orientation dispersion and density imaging(NODDI)in characterizing the brain tissue microstructural changes of middle cerebral artery occlusion(MC...The purpose of this work was to demonstrate the feasibility of neurite orientation dispersion and density imaging(NODDI)in characterizing the brain tissue microstructural changes of middle cerebral artery occlusion(MCAO)in rats at 3T MRI,and to validate NODDI metrics with histology.A multi-shell diffusion MRI protocol was performed on 11 MCAO rats and 10 control rats at different post-operation time points of 0.5,2,6,12,24 and 72 h.NODDI orientation dispersion index(ODI)and intracellular volume fraction(V_(ic))metrics were compared between MCAO group and control group.The evolution of NODDI metrics was characterized and validated by histology.Infarction was consistent with significantly increased ODI and V_(ic)in comparison to control tissues at all time points(P<0.001).Lesion ODI increased gradually from 0.5 to 72 h,while its V_(ic)showed a more complicated and fluctuated evolution.ODI and V_(ic)were significantly different between hyperacute and acute stroke periods(P<0.001).The NODDI metrics were found to be consistent with the histological findings.In conclusion,NODDI can reflect microstructural changes of brain tissues in MCAO rats at 3T MRI and the metrics are consistent with histology.This study helps to prepare NODDI for the diagnosis and management of ischemic stroke in translational research and clinical practice.展开更多
The prevalence of neurodegenerative diseases is increasing as human longevity increases. The objective biomarkers that enable the staging and early diagnosis of neurodegenerative diseases are eagerly anticipated. It h...The prevalence of neurodegenerative diseases is increasing as human longevity increases. The objective biomarkers that enable the staging and early diagnosis of neurodegenerative diseases are eagerly anticipated. It has recently become possible to determine pathological changes in the brain without autopsy with the advancement of diffusion magnetic resonance imaging techniques. Diffusion magnetic resonance imaging is a robust tool used to evaluate brain microstructural complexity and integrity, axonal order, density, and myelination via the micron-scale displacement of water molecules diffusing in tissues. Diffusion tensor imaging, a type of diffusion magnetic resonance imaging technique is widely utilized in clinical and research settings;however, it has several limitations. To overcome these limitations, cutting-edge diffusion magnetic resonance imaging techniques, such as diffusional kurtosis imaging, neurite orientation dispersion and density imaging, and free water imaging, have been recently proposed and applied to evaluate the pathology of neurodegenerative diseases. This review focused on the main applications, findings, and future directions of advanced diffusion magnetic resonance imaging techniques in patients with Alzheimer's and Parkinson's diseases, the first and second most common neurodegenerative diseases, respectively.展开更多
了解年老过程中大脑在细胞水平上发生的变化对于揭示老年人认知功能下降的原因有重要意义。扩散MRI(diffusion MRI,d MRI)技术是目前惟一可以无创探查活体组织微观结构的方法。扩散张量成像(DTI,diffusion tensor imaging)是临床上最常...了解年老过程中大脑在细胞水平上发生的变化对于揭示老年人认知功能下降的原因有重要意义。扩散MRI(diffusion MRI,d MRI)技术是目前惟一可以无创探查活体组织微观结构的方法。扩散张量成像(DTI,diffusion tensor imaging)是临床上最常用的一种d MRI技术,但是由于某些固有缺陷,它不能充分刻画大脑组织的微观结构。作者介绍三种可以有效弥补DTI不足的新型扩散成像方法:扩散峰度成像(diffusion kurtosis imaging,DKI),扩散的受阻受限合成模型(composite hindered and restricted model of diffusion,CHARMED)和神经突方向离散度与密度成像(neurite orientation dispersion and density imaging,NODDI)。联合使用DTI和这些新技术,研究者可以更深入地了解年老如何影响大脑的微观结构。展开更多
目的利用神经突方向离散度与密度成像(neurite orientation dispersion and density imaging,NODDI)探索帕金森病患者(Parkinson’s disease,PD)灰质核团微结构变化。材料与方法对36例PD患者和26例健康者进行MRI扫描和NODDI图像后处理,...目的利用神经突方向离散度与密度成像(neurite orientation dispersion and density imaging,NODDI)探索帕金森病患者(Parkinson’s disease,PD)灰质核团微结构变化。材料与方法对36例PD患者和26例健康者进行MRI扫描和NODDI图像后处理,比较两组神经突体积分数(intracellular volume fraction,Vic)、神经突方向分散度(orientation dispersion index,ODI),通过受试者工作特征曲线(receiver operating characteristic curve,ROC曲线)评估不同核团Vic值诊断效能。结果与对照组相比,PD患者左侧黑质(P<0.001)、丘脑(P=0.003)及右侧尾状核头(P=0.002)、壳核(P<0.001)、苍白球(P<0.001)、黑质(P<0.001)、红核(P<0.001)、丘脑(P=0.006)Vic值差异有统计学意义,且左侧黑质(P<0.001)及右侧尾状核头(P=0.038)、壳核(P=0.001)、苍白球(P=0.023)、黑质(P<0.001)、红核(P=0.023)ODI值差异有统计学意义。ROC曲线显示,右侧黑质、红核、苍白球、壳核Vic指标诊断PD的曲线下面积(area under curve,AUC)分别为0.861、0.788、0.852、0.843。此外,右侧黑质苍白球及黑质壳核Vic值联合诊断PD的AUC分别为0.925、0.921。结论NODDI技术可以定性区分PD患者和健康人群,量化分析PD脑深部灰质核团微结构改变情况。Vic指标在黑质部位显示出最佳诊断效能,且黑质苍白球及黑质壳核的联合诊断的诊断效能均优于单一核团,这一发现为PD诊断提供新的神经影像学支持。展开更多
目的探讨磁共振神经突方向离散度与密度成像(neurite orientation dispersion and density imaging,NODDI)对帕金森病患者的临床应用价值。材料与方法收集我院41例帕金森病(Parkinson’s disease)患者和22名年龄和性别匹配的正常志愿者...目的探讨磁共振神经突方向离散度与密度成像(neurite orientation dispersion and density imaging,NODDI)对帕金森病患者的临床应用价值。材料与方法收集我院41例帕金森病(Parkinson’s disease)患者和22名年龄和性别匹配的正常志愿者作为对照组进行磁共振平扫和NODDI,量化分析PD患者壳核(putamen)的变化,在组间比较壳核的细胞内体积分数(entracellular volume fraction,Vic)、方向分散指数(orientation dispersion index,ODI)和各向同性体积分数(volume fraction of the isotropic compartment,Viso)。多因素Logistic分析确定PD的独立预测因子。结果PD患者壳核中的Vic、ODI明显低于健康对照组(P<0.05)。多因素Logistic分析显示,PD患者壳核中的Vic值的变化与PD的相关性具有统计学意义(P<0.05),壳核中的Vic值是PD的独立预测因子。在ROC分析中,患者对侧壳核中的Vic显示出最佳的诊断性能。结论NODDI可能有助于诊断PD。展开更多
目的应用磁共振神经突起方向离散度与密度成像(neurite orientation dispersion and density imaging,NODDI)定量分析肝豆状核变性(Wilson disease)基底核及丘脑核团微结构改变,并评估各核团NODDI改变与WD神经精神症状的相关性.方法收...目的应用磁共振神经突起方向离散度与密度成像(neurite orientation dispersion and density imaging,NODDI)定量分析肝豆状核变性(Wilson disease)基底核及丘脑核团微结构改变,并评估各核团NODDI改变与WD神经精神症状的相关性.方法收集24例定期排铜的WD患者(WD组)和年龄性别相匹配的25名正常对照(正常对照组)的双侧尾状核、壳核、苍白球和丘脑的NODDI数据,主要参数包括神经突内体积分数(intraneurite volume fraction,Vic)、神经突方向离散度(orientation dispersion index,ODI)和脑脊液体积分数(isotropic volume fraction,Viso),比较各核团三项参数与正常对照组差异.分析WD患者改良Young量表与WD患者的NODDI参数的相关性.利用受试者工作特征曲线ROC分析NODDI各参数诊断WD患者的诊断效能.结果WD组与正常对照组相比,双侧尾状核、壳核、苍白球Vic值和ODI值均减少,而Viso值增加(均P<0.05);双侧丘脑Vic值降低,Viso值增加(均P<0.05),ODI不具有统计学差异(P>0.05).WD组分型之间各核团NODDI参数比较无统计学差异(均P>0.05).WD组肢体肌张力严重程度和左侧苍白球Vic值负相关(r=-0.425,P=0.038);震颤严重程度与左侧苍白球(r=-0.437,P=0.033)、左侧壳核(r=-0.541,P=0.006)、左右侧丘脑(r=-0.556,P=0.005;r=-0.493,P=0.014)的Vic值呈负相关;舞蹈样症状严重程度和左侧尾状核(r=-0.461,P=0.024)、左侧壳核(r=-0.489,P=0.015)Vic值呈负相关;高级神经功能评分和左侧苍白球(r=-0.562,P=0.004)、壳核(r=-0.570,P=0.004)、右侧苍白球(r=-0.679,P<0.001)、右侧丘脑(r=-0.490,P=0.015)的Vic值,左侧苍白球ODI值(r=-0.440,P=0.031)呈负相关.ROC曲线分析得到右侧丘脑Vic值、左侧尾状核ODI值、右侧尾状核Viso值对WD患者具有最佳诊断效能.结论不同临床症状表现WD患者核团NODDI改变不同,不同核团NODDI参数改变与临床症状具有一定相关性.展开更多
基金National Natural Science Foundation of China(No.81570462,No.81730049,and No.81801666).
文摘The purpose of this work was to demonstrate the feasibility of neurite orientation dispersion and density imaging(NODDI)in characterizing the brain tissue microstructural changes of middle cerebral artery occlusion(MCAO)in rats at 3T MRI,and to validate NODDI metrics with histology.A multi-shell diffusion MRI protocol was performed on 11 MCAO rats and 10 control rats at different post-operation time points of 0.5,2,6,12,24 and 72 h.NODDI orientation dispersion index(ODI)and intracellular volume fraction(V_(ic))metrics were compared between MCAO group and control group.The evolution of NODDI metrics was characterized and validated by histology.Infarction was consistent with significantly increased ODI and V_(ic)in comparison to control tissues at all time points(P<0.001).Lesion ODI increased gradually from 0.5 to 72 h,while its V_(ic)showed a more complicated and fluctuated evolution.ODI and V_(ic)were significantly different between hyperacute and acute stroke periods(P<0.001).The NODDI metrics were found to be consistent with the histological findings.In conclusion,NODDI can reflect microstructural changes of brain tissues in MCAO rats at 3T MRI and the metrics are consistent with histology.This study helps to prepare NODDI for the diagnosis and management of ischemic stroke in translational research and clinical practice.
基金supported by research grants from the program for Brain/MINDS Beyond program from the Japan Agency for Medical Research and Development(AMED)under Grant Number JP18dm0307024(to KK)MEXT-Supported Program for the Private University Research Branding Project+1 种基金ImPACT Program of Council for Science,Technology and Innovation(Cabinet Office,Government of Japan)JSPS KAKENHI Grant Number JP16K10327(to KK)
文摘The prevalence of neurodegenerative diseases is increasing as human longevity increases. The objective biomarkers that enable the staging and early diagnosis of neurodegenerative diseases are eagerly anticipated. It has recently become possible to determine pathological changes in the brain without autopsy with the advancement of diffusion magnetic resonance imaging techniques. Diffusion magnetic resonance imaging is a robust tool used to evaluate brain microstructural complexity and integrity, axonal order, density, and myelination via the micron-scale displacement of water molecules diffusing in tissues. Diffusion tensor imaging, a type of diffusion magnetic resonance imaging technique is widely utilized in clinical and research settings;however, it has several limitations. To overcome these limitations, cutting-edge diffusion magnetic resonance imaging techniques, such as diffusional kurtosis imaging, neurite orientation dispersion and density imaging, and free water imaging, have been recently proposed and applied to evaluate the pathology of neurodegenerative diseases. This review focused on the main applications, findings, and future directions of advanced diffusion magnetic resonance imaging techniques in patients with Alzheimer's and Parkinson's diseases, the first and second most common neurodegenerative diseases, respectively.
文摘了解年老过程中大脑在细胞水平上发生的变化对于揭示老年人认知功能下降的原因有重要意义。扩散MRI(diffusion MRI,d MRI)技术是目前惟一可以无创探查活体组织微观结构的方法。扩散张量成像(DTI,diffusion tensor imaging)是临床上最常用的一种d MRI技术,但是由于某些固有缺陷,它不能充分刻画大脑组织的微观结构。作者介绍三种可以有效弥补DTI不足的新型扩散成像方法:扩散峰度成像(diffusion kurtosis imaging,DKI),扩散的受阻受限合成模型(composite hindered and restricted model of diffusion,CHARMED)和神经突方向离散度与密度成像(neurite orientation dispersion and density imaging,NODDI)。联合使用DTI和这些新技术,研究者可以更深入地了解年老如何影响大脑的微观结构。
文摘目的探讨磁共振神经突方向离散度与密度成像(neurite orientation dispersion and density imaging,NODDI)对帕金森病患者的临床应用价值。材料与方法收集我院41例帕金森病(Parkinson’s disease)患者和22名年龄和性别匹配的正常志愿者作为对照组进行磁共振平扫和NODDI,量化分析PD患者壳核(putamen)的变化,在组间比较壳核的细胞内体积分数(entracellular volume fraction,Vic)、方向分散指数(orientation dispersion index,ODI)和各向同性体积分数(volume fraction of the isotropic compartment,Viso)。多因素Logistic分析确定PD的独立预测因子。结果PD患者壳核中的Vic、ODI明显低于健康对照组(P<0.05)。多因素Logistic分析显示,PD患者壳核中的Vic值的变化与PD的相关性具有统计学意义(P<0.05),壳核中的Vic值是PD的独立预测因子。在ROC分析中,患者对侧壳核中的Vic显示出最佳的诊断性能。结论NODDI可能有助于诊断PD。
