Correction: FI = Sum-over-vertices[ |kmax|(|kmax|-|kmin|)]/SurfaceArea On Sep 28, 2011, at 1:38 PM, Donna Dierker wrote:
> My understanding is that GI is also a global summary stat across the whole > hem, while lGI is *local* GI (vertex-wise). It measures how folded the > cortex is at that vertex. GI and lGI are based on area, while the folding > index is based on curvature. Truly different measures. > > Gyrification Index (GI) = Pial surface area / Convex hull surface area > (Zilles et al., 1988) > > Folding Index (FI) = |kmax|(|kmax|-|kmin|) > Van Essen and Drury 1997 > > On Sep 28, 2011, at 10:48 AM, Nick Schmansky wrote: > >> have a look at this page: >> >> https://surfer.nmr.mgh.harvard.edu/fswiki/LGI >> >> folding index is typically a single number summarizing the amount of >> folding overall on a surface. freesurfer puts these measures in >> subjid/stats/?h.curv.stats. >> >> gyrification index is a new method created by maria schaer to create a >> surface-based measure of folding (points across a surface describing the >> local folding measures). >> >> n. >> >> >> On Wed, 2011-09-28 at 11:05 -0400, Alan Francis wrote: >>> Hi Bruce, Nick & Doug: >>> >>> How does Folding index differ from Gyrification index? >>> >>> thanks, >>> >>> Alan >>> >>> BIDMC >>> _______________________________________________ >>> Freesurfer mailing list >>> Freesurfer@nmr.mgh.harvard.edu >>> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >> >> _______________________________________________ >> Freesurfer mailing list >> Freesurfer@nmr.mgh.harvard.edu >> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >> >> >> 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. > > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
