Yes, the avg.area files have the average over the input subjects at each vertex. I've used it to overcome this problem. doug
On 5/12/11 8:04 AM, Bruce Fischl wrote: > Hi Boris, > > 1. Doug can say for sure, but I believe so. > 2. No. The mid surface doesn't correspond to any boundary in the image and > so we are always hesitant to provide any morphometric measures for it. We > are working on a more explicit estimation of the location of layer IV, but > that is a future direction. You could generate it yourself easily enough > though. > > cheers > Bruce > > > On Thu, 12 May 2011, Boris Bernhardt > wrote: > >> 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 > > _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
