We are trying to run some longitudinal data using FreeSurfer 7.4.1.

We have one group and 3 scans. We would like to see the changes between these timepoints. 

I am not sure how to proceed with the GLM because I found two tutorials.

One here is saying I should create a longitudinal qdec table including fsid-base column and years/timepoints then run mri_glmfit --osgm

The other one is saying to do a paired analysis. This one does not include the base and years data. 

How should I proceed?

Thank you!

Best regards,

Eszter