Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin Madison, Madison, WI, USA.
Neuroimage. 2013 Sep;78:463-73. doi: 10.1016/j.neuroimage.2013.04.013. Epub 2013 Apr 15.
Resting-state fMRI (rs-fMRI) has been demonstrated to have moderate to high reliability and produces consistent patterns of connectivity across a wide variety of subjects, sites, and scanners. However, there is no one agreed upon method to acquire rs-fMRI data. Some sites instruct their subjects, or patients, to lie still with their eyes closed, while other sites instruct their subjects to keep their eyes open or even fixating on a cross during scanning. Several studies have compared those three resting conditions based on connectivity strength. In our study, we assess differences in metrics of test-retest reliability (using an intraclass correlation coefficient), and consistency of the rank-order of connections within a subject and the ranks of subjects for a particular connection from one session to another (using Kendall's W tests). Twenty-five healthy subjects were scanned at three different time points for each resting condition, twice the same day and another time two to three months later. Resting-state functional connectivity measures were evaluated in motor, visual, auditory, attention, and default-mode networks, and compared between the different resting conditions. Of the networks examined, only the auditory network resulted in significantly higher connectivity in the eyes closed condition compared to the other two conditions. No significant between-condition differences in connectivity strength were found in default mode, attention, visual, and motor networks. Overall, the differences in reliability and consistency between different resting conditions were relatively small in effect size but results were found to be significant. Across all within-network connections, and within default-mode, attention, and auditory networks statistically significant greater reliability was found when the subjects were lying with their eyes fixated on a cross. In contrast, primary visual network connectivity was most reliable when subjects had their eyes open (and not fixating on a cross).
静息态功能磁共振成像（rs-fMRI）已被证明具有中等至高度的可靠性，并在广泛的研究对象、地点和扫描仪中产生一致的连接模式。然而，目前还没有一种被普遍认可的方法来获取 rs-fMRI 数据。有些研究机构要求其研究对象或患者在闭眼状态下保持静止，而其他研究机构则要求其研究对象在扫描过程中保持睁眼，甚至注视一个十字。已有几项研究比较了这三种静息状态下的连接强度。在我们的研究中，我们评估了测试-重测可靠性的指标差异（使用组内相关系数），以及在一个研究对象内部连接的等级顺序的一致性，以及在一个特定连接中从一个会话到另一个会话的研究对象的等级顺序的一致性（使用 Kendall W 检验）。25 名健康受试者在三种不同的静息状态下进行扫描，每种状态在一天内进行两次扫描，另外两次扫描在两到三个月后进行。评估了静息状态功能连接的测量指标，这些指标在运动、视觉、听觉、注意力和默认模式网络中进行了评估，并比较了不同静息状态下的测量结果。在所检查的网络中，只有在闭眼状态下，听觉网络的连接强度显著高于其他两种状态。在默认模式、注意力、视觉和运动网络中，没有发现连接强度在不同静息状态下的显著差异。总体而言，不同静息状态下的可靠性和一致性差异在效应大小上相对较小，但结果仍然显著。在所有的网络内连接中，以及在默认模式、注意力和听觉网络中，当研究对象的眼睛固定在一个十字上时，发现了统计上显著更高的可靠性。相比之下，当研究对象睁开眼睛（并且不固定在一个十字上）时，初级视觉网络的连接最可靠。
