Do you mean cortical masks? If so, then {lh,rh}.ribbon.mgz are binary masks. You can convert them to nifti with:

mri_convert lh.ribbon.mgz lh.ribbon.nii

doug

Anil Roy wrote:
Hello all,

Is there a method to generate a gray matter mask in Freesurfer that can be fed into AFNI. Could you please point me to any existing documentation on the FS wiki that already does this as I was unable to find anything.

Thanks a lot,

Anil.

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