Hi Robin

If you run-recon-all you will get a map that we call “sulc” for each subject. When we generated our original manual parcellations we used it to guide where to place the boundary between a sulcus and a gyrus. Essentially we used the zero-crossing of sulc. Load it on an white surface and see if that works for you.

Cheers Bruce

From: freesurfer-bounces@nmr.mgh.harvard.edu freesurfer-bounces@nmr.mgh.harvard.edu On Behalf Of Robin Cash Sent: Wednesday, July 21, 2021 1:35 AM To: freesurfer@nmr.mgh.harvard.edu Cc: Andrew Zalesky andrewzalesky@gmail.com Subject: [Freesurfer] delineating gyral boundaries in native space

External Email - Use Caution Hi, Is there a tool within freesurfer that can be used to delineate gyral boundaries (delineate sulci) from an individual's T1 scan in native space? To be clear, the purpose wouldn't be to broadly identify or parcellate different gyri, but to delineate the boundary between gyri and sulci. Many thanks, Robin

Dr. Robin Cash (PhD) | ARC Senior Research Fellow

Department of Biomedical Engineering,

UNIVERSITY OF MELBOURNE Melbourne Neuropsychiatry Centre, Level 3,

Alan Gilbert Building,

161 Barry St,

Carlton VIC 3053 Australia

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