Test-retest Reliability For Measuring Regional Difference During Resting State

The human brain is a complex dynamic system. Considering of the unconstrained feature, the reliability of the brain activity during resting state deserves to be study.Now, more and more researches begin to pay attention to the resting state study, most of them only pay attention to one state (eyes-open or eyes-closed) for the reliability study, rare of them focus on the modulation of different states, but the later one is exactly what majority resting state fMRI study focus on content. Early studies have found that there is high reliability between eyes open and eyes closed for the spontaneous brain activity. However, these researches only studied the spatial pattern of the group results which can also be called statistic results, the factors which affect the difference between states were not be analyzed seriously.In this research, we studied two questions:the first one is that whether the time will influence the reliability of regional brain activity between eyes open and eyes closed at the individual level, the second one is that whether the machine will affect the stability of the group results (multi-center study). We combined BOLD (Blood oxygen level dependent) and ASL (Arterial spin labeling) techniques, using three index, such as, ALFF (Amplitude of low frequency), ReHo (Regional homogeneity), CBF (Cerebral blood flow) to study the reliability between different states from dynamic and stable aspects.At the individual level, the results show that the stable regional brain activity between eyes open and eyes closed found by ALFF, ReHo and CB were located in sensorimotor area, auditory cortex, Lines outside surface and frontal cortex. The multi-center results show that the location of the stable regional activity found by ReHo was Similar with the results at the individual level, the stable of the regional activity found by ALFF were located in primary visual cortex not in in the Lines outside surface, this is the big difference compared with ReHo. The stable results of CBF is primary visual and thalamus.From this study we can conclude that the regional brain activity between different states is stable at the individual level and the multi-center result is also stable.