Dear all,
I am using Freesurfer longitudinal analysis to detect the relationship between the change of thickness in patients and a clinical test (ex: MMSE). I just have MRI of patients at two time points (baseline and followup) without normal control subjects. I have already completed longitudinal analysis following Freesurfer instruction. Now I am not sure how to design the FSDG file and contrast vector. I want to measure whether the change of thickness of patients (from baseline to followup) has some relationship with MMSE. Mean thickness of the brain is a covariate. The following is the FSDG and contrast I designed. Can anyone help me have a look whether it is right?
Thanks in advance!
Joe
FSGD:
GroupDescriptorFile 1
Title MMSEandthickness
Class Baseline
Class Followup
Variable MMSE mean_thickness
Input subject1 Baseline 21 2.6
Input subject2 followup 18 2.7
. . .
Contrast: 1 -1 0.5 0.5 0 0