I want to convert fs volume into MNI space so I can get some ROIs in MNI space
I tried using the mri_vol2vol function in free surfer
mri_vol2vol --mov Subject_FS1mm.nii.gz --targ MNI152_T1_1mm_brain.nii.gz --o Subject_MNI_FS1mm.nii.gz
Subject_FS1mm.nii.gz - volume I want to convert
MNI152_T1_1mm_brain.nii.gz - reference template
Subject_MNI_FS1mm.nii.gz - name of output file
However, I am getting and error " error: File exists
error: ERROR: no registration (R) is specified"
Is there any work around it