[Freesurfer] mgz to nii.gz... T1 and ROIs. Is there a way to do (5) from command line?

Hi FS expert. I need to port my T1 and a couple of ROIs from mgz to nii.gz. The same for many subjects. The issue's about dimensions. When I use fslview, it respond me that "All overlays must have same dimensions as the base image!". Indeed T1's 256x256x256 with voxel sizee 1mm3, ROIs are differents dimensions and 0.5mm3 voxel size. To work now I use this pipeline:

( command line :) ) 1) mri_convert ---> nii 2) gzip ---> nii.gz 3) fslmaths t1 -sub t1 t1_zero 4) mricron t1_zero -l 0 -h 100 -o roi1.nii.gz ( GUI only :( ) 5) (from mricron) save as nifti roi1_ok.nii.gz

Is there a way to do (5) from command line?

Thanx

Riccardo