[Freesurfer] poor image quality and re-running freesurfer

Hello,

I have a couple of subjects with poor quality scans. The grey/white contrast is not so good. I wonder if the newest version of freesurfer might help with the pial and white surfaces.

Do I need to make some minor edits to key images/files in order to force freesurfer to take a second shot at these subjects? For example, can I just rerun these subjects with the new version? Or do I need to make some edits in order to have freesurfer re-evaluate the brain mask, wm.mgz, and surfaces. For example, should I make a minor edit to the brainmask.mgz and the wm.mgz files in order for freesurfer to detect that it needs to redo those parts.

Thank you, Christine