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