Can anybody comment on the new dura_thresh flag? See below,

Many thanks,

Octavian.

---------- Forwarded message ---------- From: Octavian Lie octavian.lie@gmail.com Date: Sat, Mar 11, 2017 at 9:28 AM Subject: -dura_thresh To: "freesurfer@nmr.mgh.harvard.edu" freesurfer@nmr.mgh.harvard.edu

Dear All,

In FS6.0.0, this flag is added to manually adjust watershed threshold instead of its automatic calculation. I went back to the original paper by Segonne et al, and I could identify the prefllooding height h and the post watershed threshold t. I assume the flag refers to the latter. Since the threshold varies between subjects, where is it specified in the log file of a recon-all run? Also, could you indicate a (narrow) range one could start with if trying to manually adjust a run, based on your experience? Also, what is the watershed direction based on t (higher t values lead to more aggressive dura removal, or the other way around?

Thank you very much,

Octavian