Dear FreeSurfer Team,

I am working with two timepoints for a subject and attempting to create a template for samseg-long using


mri_robust_template

. However, I encountered an error related to voxel size mismatch between the input images. Both timepoint images are T1W.

The command I ran is:

mri_robust_template --mov subject1_preRT.nii subject1_postRT.nii --template mean.mgz --satit --mapmov subject1_preRT_reg.mgz 
subject1_postRT_reg.mgz

I received the following error:

ERROR: MultiRegistration::loadMovables: images have different voxel sizes.
  Currently not supported, maybe first make conform?
  Debug info: size(1) = 0.428571, 0.428571, 4.4   size(0) = 0.449219, 0.449219, 5
error: Operation not permitted
error: MultiRegistration::loadMovables: voxel size is different subject1_postRT.nii.

>From what I understand,


mri_robust_template

does not support different voxel sizes between input images. Would the recommended approach be to first resample the images to the same voxel size using


mri_convert --conform

or another method before running


mri_robust_template

Additionally, would this resampling introduce any potential biases that I should be aware of in a longitudinal analysis? If there is a better way to handle this issue, I would greatly appreciate your guidance.

Best regards,

Nima