Dear FSL users,
Hello, I’ve been through the analysis of my diffusion data using TBSS, and I’ve done the correlation analysis of global diffusion changes (skeleton FA, FA, MD, RD and AD for the whole brain) and certain variable. And then, went through the correlation analysis of local diffusion changes (FA, MD, RD and AD) afterwards using the same variable to locate each white matter connections attributable for the change of the parameter. Then I came up to a question as follows:
Looking back at the previous papers using global and correlation analysis with TBSS, they seemed to have been dealt separately. As for the relationship between the global diffusion measure and the local one, can we regard them as independent with each other? In case not, isn’t it necessary for going through the process like the one used in PET data analysis like using ANCOVA to get rid of the effect of the global CBF to go through the local CBF analysis? If so, is such procedure using the global diffusion measures as a covariate to go through the local diffusion analysis necessary?
Thank you very much for your help in advance.
Best,
Kazumi
|