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: mkaras@iu.edu
_______________________________________________
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.eduhttps://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.