I'm trying to create a ROI based on peak significance voxel from a paper. They reported a peak at X=21, Y=-71, Z=22 and area of 4,620 mm², based on MNI305. My idea was creating a sphere ROI around this voxel and check its area in the brain image.

To do so I'm using the following command:

mri_volsynth --template $SUBJECTS_DIR/fsaverage/mri/brainmask.mgz \
--pdf delta --c_ras 21 -71 22 --res 1 1 1 1 --dim 7 7 7 1 --o ROI.sm00.mgh

I also tried with --c_ras 107 106 57, that is the value of this point on brainmask.mgz

However, when I visualize the surface created with freeview  my ROI is always in the center of the brainmask.mgz. And if I try to smooth this surface using mris_fwhm it exits with error.

Can someone help me with this?

Thanks,

Mauricio