Morphometry Stats
Gray Matter and White Matter Volume
Estimation of the gray matter and white matter volumes should be taken from the surfaces, and not from the aseg. The program mris_volume will compute the volume inside a surface. It should be run from within the <subjid>/surf directory with the following command:
mris_volume ?h.surface
where ?h.surface is replaced with the specific surface you are looking for the volume of.
To get the gray matter volume you should use the following formula:
gm volume = pial volume - white volume
To get the white matter volume the program mris_wm_volume will calculate the wm volume, using the command:
mris_wm_volume <subject> <hemi>