Hello Freesurfer,

I have 3 PET images per individual. I am learning PetSurfer based on the Greve et al., 2014 paper. 

On the PetSurfer link, there are 2 methods.

mri_convert pet.nii.gz —frame frameno template.nii.gz 

or

mri_concat pet.nii.gz --mean —0 template.nii.gz

What are the differences? My files are listed as subject123_a.nii.gz, subject123_b.nii.gz, subject123_c.nii.gz

Is "mri_concat subject123_a.nii.gz, subject123_b.nii.gz, subject123_c.nii.gz —mean —o template.nii.gz” correct?

Thank you for helping.

Best Wishes,

S