Re: [Freesurfer] questions about SurfArea and meancurv

-- Daniel Yang, PhD Postdoctoral Researcher Child Study Center Yale University 203-737-5454 On 7/24/12 9:58 AM, "Bruce Fischl" fischl@nmr.mgh.harvard.edu wrote: >Hi Daniel > >sorry, I meant to respond to your previous post. We generate statistics >for both the white and pial surfaces. For historical reasons the ones >without specific surface name in them represent the white surface (i.e. >the >pial ones will all say "pial"). We can produce both Gaussian and Mean >curvature measures, but in general the one we use most is the mean >curvature as it is a more intuitive representation of geometry than the >Gaussian one (and the Gaussian curvature is also a lot noisier, since it >is >the product of two curvature measures). > >cheers >Bruce > >On Tue, 24 Jul 2012, Yang, Daniel wrote: > >> Dear all, >> >> After studying the freesurferstats2table script for a while, I think I >>figure out what these surfaces are. >> Below is my understanding. Please correct me if I am mistaken! >> >> In the aparc_area_lh.txt, the surface area should be one based on the >>pial surface, not the white surface, >> because we are talking about cortical area. >> >> In the aparc_meancurv_lh.txt, the mean curvature should be one based on >>the Gaussian Curvature of the white >> surface, not the pial surface, because it is how curvature is computed >>in freesurfer. >> >> Thanks! >> Daniel >> -- >> Daniel Yang, PhD >> Postdoctoral Researcher >> Child Study Center >> Yale University >> 203-737-5454 >> >> From: <Yang>, Daniel Yang yung-jui.yang@yale.edu >> Date: Thursday, July 19, 2012 11:51 PM >> To: "freesurfer@nmr.mgh.harvard.edu" freesurfer@nmr.mgh.harvard.edu >> Subject: questions about SurfArea and meancurv >> >> Dear Freesurfer, >> >> I am new to freesurfer and have a number of beginner's questions. After >>recon all the subjects and running >> the freesurferstats2table script, I am looking at the two files: >>aparc_area_lh.txt and aparc_meancurv_lh.txt. >> Everything goes by default. >> >> My questions are, >> >> 1. In the aparc_area_lh.txt, is the surface area based on the pial >>surface, the white surface, or both? >> 2. In the aparc_meancurv_lh.txt, is it based on the Gaussian Curvature >>of the white surface or the pial >> surface? >> >> I cannot find the relevant documentation in the freesurfer wiki. Any >>comments are highly appreciated! >> >> Best Regards, >> Daniel >> -- >> Daniel Yang, PhD >> Postdoctoral Researcher >> Child Study Center >> Yale University >> 203-737-5454 >> >> > > >The information in this e-mail is intended only for the person to whom it >is >addressed. If you believe this e-mail was sent to you in error and the >e-mail >contains patient information, please contact the Partners Compliance >HelpLine at >http://www.partners.org/complianceline . If the e-mail was sent to you in >error >but does not contain patient information, please contact the sender and >properly >dispose of the e-mail.