http://brainvis.wustl.edu/wiki/index.php/Folding/Measurements
On 02/20/2016 01:22 PM, Bruce Fischl wrote: > Hi Marta > > A 2D surface (like the cortical white or pial models) has two > principal curvatures at each point - one in the direction of maximum > curvature and one in the direction of minimum curvature - typically > denoted k1 and k2. The mean curvature is the average of these > H=(k1+k2)/2 and the Gaussian curvature is the product of them K=(k1 * > k2). So, MeanCurv is the integral of the absolute value of H and > GausCurv is the integral of the absolute value of K. FoldInd and > CurvInd are two indices proposed by David Van Essen in a paper from > years ago that we also compute. Sorry, I don't have the right > reference handy, perhaps someone else on the list does? > > cheers > Bruce > > > On Tue, 16 Feb 2016, Karas, Marta wrote: > >> >> H! >> >> I am working with data which is an output from the FreeSurfer >> processing. >> >> I would like to kindly ask you to refer me to materials / precise >> "mathematical" definitions that could help to understand what are the >> following parameters: >> * ​MeanCurv - Integrated Rectified Mean Curvature, >> * GausCurv - Integrated Rectified Gaussian Curvature, >> * FoldInd - Folding Index, >> * CurvInd - Intrinsic Curvature Index. >> (I have been trying to google but not been successful, unfortunately.) >> >> Kind regards, >> >> >> Marta Karas, M.S. >> >> Research Assistant, Department of Biostatistics >> >> Richard M. Fairbanks School of Public Health and School of Medicine >> >> Indiana University >> >> tel: 317-665-4551 >> >> email: mka...@iu.edu >> >> >> >> > > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer -- Douglas N. Greve, Ph.D. MGH-NMR Center gr...@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422 Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 www.nmr.mgh.harvard.edu/facility/filedrop/index.html Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/ _______________________________________________ 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.
