Relationship between simultaneously acquired resting-state regional cerebral glucose metabolism and functional MRI: A PET/MR hybrid scanner study
Relationship between simultaneously acquired resting-state regional cerebral glucose metabolism and functional MRI: A PET/MR hybrid scanner study
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DOI：
10.1016/j.neuroimage.2015.03.017
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发表时间：
2015-06-01
期刊：
影响因子：
5.7
通讯作者：
Quarantelli, Mario
中科院分区：
文献类型：
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作者：
Aiello, Marco;Salvatore, Elena;Quarantelli, Mario
最近推出的混合PET/MR扫描仪提供了同时测量的机会，并在直接的空间对应，代谢需求和大脑的功能活动，从而捕捉大脑的生理状态的补充信息。在此，我们利用PET/MR同步成像来探讨静息态氟脱氧葡萄糖-PET（FDG-PET）和功能磁共振成像（rs-fMRI）提供的代谢信息之间的关系，从23名受试者的rs-fMRI数据中生成区域均匀性（ReHo）、低频波动幅度分数（fALFF）和中心性程度（DC）图，并与由同时采集的FDG-PET提供的葡萄糖摄取分布进行逐体素比较。这四个指标中的每一对之间的相互关系进行了探讨，在相似性方面，无论是在大脑和整个组的空间分布，和跨学科的体素明智的，考虑到部分体积的影响，通过调整灰质（GM）的体积。尽管葡萄糖摄取的空间分布与rs-fMRI衍生指标之间存在显著相关性，但只有有限百分比的GM体素与受试者的PET相关。此外，PET和rs-fMRI衍生度量的空间分布之间的相关性在解剖区域和功能网络中是空间异质的，边缘系统网络中的相关强度最低（DC的斯皮尔曼rho约为-0.11），默认模式网络的相关性最强（ReHo高达0.89，fALFF为0.86）。总体而言，与DC相比，ReHo和fALFF与PET的相关系数显著更高（分别为p = 10（-8）和10（-7）），而ReHo和fALFF之间不存在显著差异。局部GM体积的变化引入了一个有限的高估的rs-fMRI FDG相关性之间的调查通过partial volume effects.These新的结果提供了基础，为未来的研究改变之间的耦合在病理条件下的脑代谢和功能连接。(C)2015 Elsevier Inc. All rights reserved.
Recently introduced hybrid PET/MR scanners provide the opportunity to measure simultaneously, and in direct spatial correspondence, both metabolic demand and functional activity of the brain, hence capturing complementary information on the brain's physiological state. Here we exploited PET/MR simultaneous imaging to explore the relationship between the metabolic information provided by resting-state fluorodeoxyglucose-PET (FDG-PET) and fMRI (rs-fMRI) in neurologically healthy subjects.Regional homogeneity (ReHo), fractional amplitude of low frequency fluctuations (fALFF), and degree of centrality (DC) maps were generated from the rs-fMRI data in 23 subjects, and voxel-wise comparison to glucose uptake distribution provided by simultaneously acquired FDG-PET was performed. The mutual relationships among each couple of these four metrics were explored in terms of similarity, both of spatial distribution across the brain and the whole group, and voxel-wise across subjects, taking into account partial volume effects by adjusting for grey matter (GM) volume. Although a significant correlation between the spatial distribution of glucose uptake and rs-fMRI derived metrics was present, only a limited percentage of GM voxels correlated with PET across subjects. Moreover, the correlation between the spatial distributions of PET and rs-fMRI-derived metrics is spatially heterogeneous across both anatomic regions and functional networks, with lowest correlation strength in the limbic network (Spearman rho around -0.11 for DC), and strongest correlation for the default-mode network (up to 0.89 for ReHo and 0.86 for fALFF). Overall, ReHo and fALFF provided significantly higher correlation coefficients with PET (p = 10(-8) and 10(-7), respectively) as compared to DC, while no significant differences were present between ReHo and fALFF. Local GM volume variations introduced a limited overestimation of the rs-fMRI to FDG correlation between the modalities under investigation through partial volume effects.These novel results provide the basis for future studies of alterations of the coupling between brain metabolism and functional connectivity in pathologic conditions. (C) 2015 Elsevier Inc. All rights reserved.