The thickness is an average of two numbers. One is the distance from a white surface vertex to the pial surface along the normal to the white. The other is the distance from the pial to the white along the normal to the pial.
Volume (in v6) is computed as the volume of a truncated tetrahedron. Prior to v6 it was surface area times thickness On 04/10/2017 12:24 PM, John Anderson wrote: > Dear Freesurfer experts, > I highly appreciate if anybody clarify how Freesurfer calculate > cortical thickness and gray matter volume. > If the cortical thickness of e.g. precentral gurus is measured as the > closest distance from the gray-white boundary to the gray-CSF boundray > at each vertex on the tessellated surface (Fischl and Dale. 2000). > How the gray matter volume for the precentral gyrus was measured? > > Thank you for any clarification! > > John > > > > _______________________________________________ > 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.
