the white is a region on the midline, probably ventricle, that we fill to create a closed surface for the cortical models. If you want a white matter mask you are better off extracting it from the aseg.mgz with mri_binarize -match
cheers Bruce On Tue, 29 Jul 2014, Alshikho, Mohamad J. wrote:
Thank you Bruce, Then what is the white area means in (wm.mgz); kindly check the attached photo ALSO do you recommend to use wm.mgz and wm.seg.mgz in order to create a mask for the white matter.
Mohamad
-----Original Message----- From: freesurfer-bounces@nmr.mgh.harvard.edu [mailto:freesurfer-bounces@nmr.mgh.harvard.edu] On Behalf Of Bruce Fischl Sent: Tuesday, July 29, 2014 1:35 PM To: Freesurfer support list Subject: Re: [Freesurfer] The difference between wm.mgz and wm.seg.mgz
Hi Mohamad
the wm.seg.mgz is the output of mri_segment and is a voxel segmentation that considers local intensities and estimated cortical geometry, but not topology. mri_pretess then takes the wm.seg.mgz and removes certain pathological voxel configurations (like corners touching) that mess up the subsequent tessellation and creates the wm.mgz
cheers Bruce
On Tue, 29 Jul 2014, Alshikho, Mohamad J. wrote:
Dear Fs Experts,
What is the difference between (wm.mgz and wm.seg.mgz)_ in the output of recon-all? i.e is wm.mgz means the whole white matter (right_left hemispheres and brain stem except the cerebellum)
Thanks
Mohamad