Hi Bruce, Thanks for the quick reply. I took the individual surface values from every subject's aseg-file and calculated the mean. Visualization was made in tksurfer with the average subject.
Thus, I am still wondering about this discrepancy. Any other hints? Thanks, H 2013/4/2 Bruce Fischl <fis...@nmr.mgh.harvard.edu> > Hi Holger > > how did you calculate the surface area? And how are you visualizing it? I > wouldn't use the surface area of the average subject for anything other > than visualization as the coordinate system is not linear. You need to > compute the surface area in the individual subject coordinates or take the > jacobians into account. > > cheers > Bruce > > > > On Tue, 2 Apr 2013, Klein, Holger wrote: > > Dear Freesurfers, >> I averaged 42 subjects with make_average_subject focusing on Heschl's >> Gyrus and finally got the image attached (for both >> atlases (Desikan = Atlas I, Destrieux = Atlas II). >> >> Gray matter surface calculations for Heschl's gyrus showed the following >> mean values (in mm^2): >> Atlas I lh = 439 (SD 60), rh = 323 (SD 46) >> Atlas II lh = 340 (SD 70), rh = 253 (SD 47) >> >> Heschl's gyrus depicted in the attached image looks considerably larger >> for Atlas II, but the surface analysis gives me >> smaller values for mean surface calculation (Atlas II < Atlas I) >> >> How can that be explained? >> >> Thanks in advance >> [cleardot.gif] >> >> Holger >> >> > _______________________________________________ > 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. > >
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