Hi Bruce, Thanks a lot for your reply.
> 2. The surface area of fsaverage is less than any individual, so you > *definitely* don't want to use it. You should map the ROI back to individuals > and compute it in the native space. I have two follow-up questions: 1) Do .pial.avg.area.mgh and/or .white.avg.area.mgh then store the mean native space surface areas for the individuals that were used to create fsaverage, and can I use these values to approximate the surface area of my ROIs then? 2) Do the avg.area files also exists somewhere for the half-thickness mid-surface? If not, does it make sense to approximate the mid-thickness surface area at each vertex by taking the mean of the corresponding pial.avg.area and white.avg.area entries? Many thanks, Boris > > cheers > Bruce > > > On Wed, 11 May 2011, Boris Bernhardt wrote: > >> Hello Freesurfer-experts, >> >> I just analyzed some FreeSurfer cortical thickness data that have been >> surface-resampled to fsaverage (using mris_surf2surf with -s fsaverage). >> >> For the visualization and reporting of my findings, I have a two questions: >> >> 1. Is there anything that conceptually speaks against showing my results on >> non-inflated surfaces of fsaverage, such as the white matter surface, the >> pial surface, or even a mid-surface model? >> >> 2. I have a couple of ROIs defined on the surface of fsaverage and want > to report the surface area of a given ROI in mm^2. Should I calculate the > area of a ROI directly from the given surface of fsaverage, or to take the > area computations from ?h.pial.avg.area.mgh/?h.white.avg.area.mgh which > represent the averages of the individuals that went into fsaverage. >> >> I am asking because I was slightly unclear of the wiki-instructions: >> https://surfer.nmr.mgh.harvard.edu/fswiki/GroupAverageSurface >> suggests to use ?h.pial.avg.area.mgh; >> >> on the other hand, the more recently edited >> http://surfer.nmr.mgh.harvard.edu/fswiki/FsAverage >> says that "The surface area of the new average subject (fsaverage) is that >> of a typical subject" >> >> I am using freesurfer 4.5.0. >> >> Hope my questions make sense and thank you very much for answering them, >> Boris >> >> >> >> >> --- >> Boris Bernhardt, PhD >> Max Planck Institute for Human Cognitive and Brain Sciences >> Stephanstr. 1a, 04103 Leipzig, Germany >> >> p: +(49) 341 9940 2658 >> e: bernha...@cbs.mpg.de >> http://www.cbs.mpg.de/~bernhardt >> >> > > > 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. > --- Boris Bernhardt Max Planck Institute for Human Cognitive and Brain Sciences Stephanstr. 1a, 04103 Leipzig, Germany p: +(49) 341 9940 2658 e: bernha...@cbs.mpg.de http://www.cbs.mpg.de/~bernhardt _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
