yes, that controls how finely the surface-based segmentations are resampled into the volume. The surface is semi-continuous so you can sample them into the volume as finely as you like. 0.5mm seems to work fine.

On 5/26/2020 4:33 PM, Julie Ottoy wrote:

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Hi,

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

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