Dear Freesurfer experts,
I want to use volume-defined ROIs (obtained in a VBM study) to extract mean thickness and surface area, in a total group of 138 participants. I followed the tutorial 'Cortical Thickness of a volume-defined ROI'. I have a few questions regarding this analysis:
1. The volume-defined ROI (i.e. orange dot) appears normal on my avg152_T1 and fsaverage. After the vol2surf-step, however, a few problems arise. The new ROIs look very different: one ROI actually consists of two clusters close to each other, one is very small and two ROIs have completely disappeared. Does anyone know why this happened?
2. When I want to obtain surface area data instead of thickness data, is it sufficient to replace 'thickness' with 'area' in the surf2surf command (it seems to work, but I want to check)? So: --sval lh.area \ --tval lh.area.fsaverage.mgh \
3. mri_segstats creates separate files for each ROI in each participant. When I want to have all thickness and area ROI data in one file, can I use asegstats2table, meas mean (it seems to work, but I want to check)?
Any help would be very much appreciated!
Anita