fMRI （Functional Magnetic Resonance Imaging） is a relatively new technique that uses MRI （Magnetic Resonance Imaging） to measure the hemodynamic response （change in blood flow） related to neural activity in the ...fMRI （Functional Magnetic Resonance Imaging） is a relatively new technique that uses MRI （Magnetic Resonance Imaging） to measure the hemodynamic response （change in blood flow） related to neural activity in the brain. This paper aims to explore and identify the obstacles facing the implementation and applications of IMRI in radiology departments within Jeddah city by analyzing related data received by direct questionnaires and interviews with all the people working in MRI units in Jeddah city and finds that the major obstacle is lacking of awareness of fMRI among medical professionals and their training.展开更多
为弥补传统的广义线性模型(generalized linear model,GLM)方法的不足,并探索模式识别在运动脑科学当中的应用价值。使用支持向量机(support vector machine,SVM)模式识别算法,以低频振幅(fractional amplitude of low-frequency fluctu...为弥补传统的广义线性模型(generalized linear model,GLM)方法的不足,并探索模式识别在运动脑科学当中的应用价值。使用支持向量机(support vector machine,SVM)模式识别算法,以低频振幅(fractional amplitude of low-frequency fluctuations,fALFF)、局部一致性(regional homogeneity,ReHo)和度中心度(degree centrality,DC)作为学习特征,对射击运动组和滑冰运动组(分类1)、射击运动组和对照组(分类2)以及速滑运动组和对照组(分类3)之间进行二分类,并计算每一个脑区在分类算法当中的权重。使用留一交叉验证法计算分类正确率,使用总的准确率、接受者操作特性曲线(receiver operating characteristic curve,ROC)、以及预测准确率来衡量机器分类算法的优劣性。结果表明:分类1中SVM算法的正确率较高且分类效果更稳定,总的准确率(total accuracy,tACC)可以维持在96.67%以上,曲线下面积(area under curve,AUC)均为1,说明SVM算法对区分不同项目运动员脑静息态功能特征时更有优势;在分类2和分类3中,SVM算法效果取决于使用的指标。其中,使用fALFF或者综合使用三个静息态指标的分类效果较稳定(tACC均在80%以上,AUC均在0.88以上);小脑在分类1算法中占较多的权重,提示不同运动项目运动员的脑功能活动之间差异最明显的部位主要在小脑上。而分类2和3中,除了小脑,还有一些与运动执行和控制及其他功能活动相关的脑区参与了算法的构成。通过SVM分类算法的应用获得较为理想的结果,展示了模式识别方法在运动科学领域的应用价值。研究成果有助于体育科学研究者从新的角度更加全面地理解运动与脑的关系。展开更多
To investigate changes of functional activation areas of the cerebral cortex and the connectivity of motor cortex networks （MCNs） in stroke patients during the recovery, five patients with the infarct in their left ...To investigate changes of functional activation areas of the cerebral cortex and the connectivity of motor cortex networks （MCNs） in stroke patients during the recovery, five patients with the infarct in their left hemispheres are recruited. Functional magnetic resonance imaging （fMRI） is performed in the second, fourth, eighth, and sixteenth weeks after the stroke. Images are analyzed using the professional software SPM5 to obtain the bilateral activation of the motor cortex in left and right handgrip tests. MCN data are extracted from the active areas, and the structural and functional characteristic parameters are computed to indicate the connectivity of the network. Results show that the ipsilesional hemisphere recruits more areas with less active extent during the handgrip test, compared with the contralesional hemisphere. MCN shows a higher overall degree of statistical independence and more statistical dependence among motor areas with the gradual recovery. It can help physicians understand the recovery mechanism.展开更多
本研究应用功能磁共振成像(functional magnetic resonance imaging,fMRI)技术,检测了健康人大脑和小脑参与空间记忆的认知过程。通过对10名右利手健康志愿者进行一项短时空间记忆任务作业的同时进行脑功能磁共振扫描,实验采用组块设计...本研究应用功能磁共振成像(functional magnetic resonance imaging,fMRI)技术,检测了健康人大脑和小脑参与空间记忆的认知过程。通过对10名右利手健康志愿者进行一项短时空间记忆任务作业的同时进行脑功能磁共振扫描,实验采用组块设计,任务与对照任务交替进行,数据采用SPM99软件进行数据分析和脑功能区定位。结果显示:当统计阈值设定为P<0.0001时,大脑皮层和右侧小脑一起被显著激活;大脑皮层所激活的脑区有双侧顶叶的楔前叶、顶上小叶、缘上回(BA7/40,BA:Brodma-nn Area),双侧前额上、中、下回(BA6/9/47),双侧枕叶和枕颞交界处(BA18/19/37),右侧海马回;左侧中脑黑质及被盖部也被激活。上述结果提示:小脑和大脑皮层一起参与了空间记忆的认知过程。展开更多
目的通过功能磁共振(functional magnetic resonance imaging,fMRI)技术,探讨精神分裂症患者静息状态下默认网络与突显网络的功能连接特点。方法采用3.0T功能磁共振技术检测27例未用药的急性期精神分裂症患者与27名年龄、性别相匹配的...目的通过功能磁共振(functional magnetic resonance imaging,fMRI)技术,探讨精神分裂症患者静息状态下默认网络与突显网络的功能连接特点。方法采用3.0T功能磁共振技术检测27例未用药的急性期精神分裂症患者与27名年龄、性别相匹配的健康对照静息状态下脑功能连接情况。使用SPM8、DPARSFA软件结合独立成分分析(independent component analysis,ICA)方法对影像学数据进行分析。结果与对照组相比,患者组默认网络中右侧额下被盖区、右侧楔前叶功能连接降低(P<0.05未校正),右侧扣带回中部、左侧额中回功能连接增高(P<0.05未校正);突显网络中左侧额下回、右侧额下回、左侧前扣带回、左侧中央后回功能连接降低(P<0.05未校正),左侧颞上回功能连接增高(P<0.05未校正)。左侧颞上回的功能连接异常与阳性与阴性症状量表中阳性症状(P)评分成正相关(r=0.568,P=0.002),右侧楔前叶的功能连接异常与妄想(P1)评分呈负相关(r=-0.458,P=0.016)。结论本研究中未用药的急性期精神分裂症患者存在静息态默认网络、突显网络的功能连接异常,部分脑区的功能连接异常与精神症状相关。展开更多
利用功能磁共振成像(functional magnetic resonance imaging,fMRI)技术解读思维数据,已经实现大脑活动的功能定位,但是大脑的思维过程具体如何运行还不得而知;利用何种分析方法更能揭示思维过程也待进一步研究.采用解决4×4数独问...利用功能磁共振成像(functional magnetic resonance imaging,fMRI)技术解读思维数据,已经实现大脑活动的功能定位,但是大脑的思维过程具体如何运行还不得而知;利用何种分析方法更能揭示思维过程也待进一步研究.采用解决4×4数独问题和图像情感反应的两种刺激任务获取思维过程数据,来分别解读不同的思维状态,探索适用于不同思维数据的分析方法.实验数据证明t-test的特征选择方法、峰值所在时间点的特征提取的方法和SVM分类算法较适用于分析这两种不同思维状态的fMRI数据,揭示正确的思维状态.展开更多
文摘fMRI （Functional Magnetic Resonance Imaging） is a relatively new technique that uses MRI （Magnetic Resonance Imaging） to measure the hemodynamic response （change in blood flow） related to neural activity in the brain. This paper aims to explore and identify the obstacles facing the implementation and applications of IMRI in radiology departments within Jeddah city by analyzing related data received by direct questionnaires and interviews with all the people working in MRI units in Jeddah city and finds that the major obstacle is lacking of awareness of fMRI among medical professionals and their training.
基金Supported by the National Natural Science Foundation of China (30670543)~~
文摘To investigate changes of functional activation areas of the cerebral cortex and the connectivity of motor cortex networks （MCNs） in stroke patients during the recovery, five patients with the infarct in their left hemispheres are recruited. Functional magnetic resonance imaging （fMRI） is performed in the second, fourth, eighth, and sixteenth weeks after the stroke. Images are analyzed using the professional software SPM5 to obtain the bilateral activation of the motor cortex in left and right handgrip tests. MCN data are extracted from the active areas, and the structural and functional characteristic parameters are computed to indicate the connectivity of the network. Results show that the ipsilesional hemisphere recruits more areas with less active extent during the handgrip test, compared with the contralesional hemisphere. MCN shows a higher overall degree of statistical independence and more statistical dependence among motor areas with the gradual recovery. It can help physicians understand the recovery mechanism.
文摘本研究应用功能磁共振成像(functional magnetic resonance imaging,fMRI)技术,检测了健康人大脑和小脑参与空间记忆的认知过程。通过对10名右利手健康志愿者进行一项短时空间记忆任务作业的同时进行脑功能磁共振扫描,实验采用组块设计,任务与对照任务交替进行,数据采用SPM99软件进行数据分析和脑功能区定位。结果显示:当统计阈值设定为P<0.0001时,大脑皮层和右侧小脑一起被显著激活;大脑皮层所激活的脑区有双侧顶叶的楔前叶、顶上小叶、缘上回(BA7/40,BA:Brodma-nn Area),双侧前额上、中、下回(BA6/9/47),双侧枕叶和枕颞交界处(BA18/19/37),右侧海马回;左侧中脑黑质及被盖部也被激活。上述结果提示:小脑和大脑皮层一起参与了空间记忆的认知过程。
文摘利用功能磁共振成像(functional magnetic resonance imaging,fMRI)技术解读思维数据,已经实现大脑活动的功能定位,但是大脑的思维过程具体如何运行还不得而知;利用何种分析方法更能揭示思维过程也待进一步研究.采用解决4×4数独问题和图像情感反应的两种刺激任务获取思维过程数据,来分别解读不同的思维状态,探索适用于不同思维数据的分析方法.实验数据证明t-test的特征选择方法、峰值所在时间点的特征提取的方法和SVM分类算法较适用于分析这两种不同思维状态的fMRI数据,揭示正确的思维状态.
