In PETsurfer gtmseg, there is the --usf (upsampling factor) which is by default 2, corresponding to 0.5 mm voxelsize. I was wondering if the usf is recommended to be chosen depending on your mri voxelsize (eg, usf 1 for 1mm voxelsize of the mri), or will it just depend on how "accurate" you want your segmentation to be? Can you safely use --usf 2 for an mri with 1mm voxelsize?

Thank you!

best regards

Julie