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Hello FreeSurfer experts,
I have a few questions on the longitudinal processing stream. I am interested in studying longitudinal morphometry changes in a pediatric population. The age range of this population is between 4-20 years with age deltas between a few months to < 2 years. I want to know what are appropriate/acceptable age deltas used for longitudinal processing. I looked through the archives and one researcher asked about age deltas. One of the answers was that “if the time delta is relatively small, this has good chances to work”. What does “relatively small” mean? If the time points exit the longitudinal pipeline without errors and the surfaces look correct, does this mean the data is relevant?? When I correct for head size, should I use the eTIV values from the cross-sectional directories or the longitudinal directories?
Thanks in advance,
Ryan Michael Nillo Staff Research Associate I University of California San Francisco Department of Radiology and Biomedical Imaging