Quantifying temporal correlations: A test-retest evaluation of functional connectivity in resting-state fMRI
Quantifying temporal correlations: A test-retest evaluation of functional connectivity in resting-state fMRI
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DOI：
10.1016/j.neuroimage.2012.09.052
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发表时间：
2013-01-15
期刊：
影响因子：
5.7
通讯作者：
Feng, Dai
中科院分区：
文献类型：
--
作者：
Fiecas, Mark;Ombao, Hernando;Feng, Dai
对功能连接性有许多解释，并提出了不同脑区BOLD信号之间时间相关性的测量方法。这些解释来自近年来出现的许多使用静息状态fMRI数据进行的功能连接性研究。然而，并非所有这些研究都使用相同的指标来量化大脑区域之间的时间相关性。在本文中，我们使用一个公共领域的重测静息态功能磁共振成像数据集进行系统的调查，经常使用的指标，在静息态功能连接（FC）的研究的稳定性。fMRI数据集是在三个不同的会话中收集的。第二次会议在第一次会议后大约11个月举行，第三次会议在第二次会议后一小时举行。FC度量由互相关、部分互相关、互相关和基于自回归模型的参数组成。我们讨论了每个指标的优点和缺点。我们使用每个FC指标进行ROI水平和全脑基于种子的体素重测分析，以评估其稳定性。对于ROI级和体素级分析，我们发现互相关比其他度量产生更稳定的测量。我们讨论了这一结果对FC指标效用的影响。我们观察到，对于负相关的ROI，它们的部分互相关向零收缩，从而影响它们的FC的稳定性。对于目前的数据集，我们发现，与第一次和第二次会议（会议之间约11个月）相比，第二次和第三次会议（会议之间一小时）之间的FC更稳定。最后，我们报告说，一些指标显示出强度和稳定性之间的正相关。总之，本文提出的结果表明，重要的影响时，选择指标量化和评估各种类型的功能连接静息态功能磁共振成像研究。(C)2012 Elsevier Inc. All rights reserved.
There have been many interpretations of functional connectivity and proposed measures of temporal correlations between BOLD signals across different brain areas. These interpretations yield from many studies on functional connectivity using resting-state fMRI data that have emerged in recent years. However, not all of these studies used the same metrics for quantifying the temporal correlations between brain regions. In this paper, we use a public-domain test-retest resting-state fMRI data set to perform a systematic investigation of the stability of the metrics that are often used in resting-state functional connectivity (FC) studies. The fMRI data set was collected across three different sessions. The second session took place approximately eleven months after the first session, and the third session was an hour after the second session. The FC metrics composed of cross-correlation, partial cross-correlation, cross-coherence, and parameters based on an autoregressive model. We discussed the strengths and weaknesses of each metric. We performed ROI-level and full-brain seed-based voxelwise test-retest analyses using each FC metric to assess its stability. For both ROI-level and voxel-level analyses, we found that cross-correlation yielded more stable measurements than the other metrics. We discussed the consequences of this result on the utility of the FC metrics. We observed that for negatively correlated ROIs, their partial cross-correlation is shrunk towards zero, thus affecting the stability of their FC. For the present data set, we found greater stability in FC between the second and third sessions (one hour between sessions) compared to the first and second sessions (approximately 11 months between sessions). Finally, we report that some of the metrics showed a positive association between strength and stability. In summary, the results presented in this paper suggest important implications when choosing metrics for quantifying and assessing various types of functional connectivity for resting-state fMRI studies. (C) 2012 Elsevier Inc. All rights reserved.