Paul, The eTIV calc in freesurfer is an estimate of the total intracranial volume based on a scaling factor determined by the alignment with an atlas. The technique is described in the paper referenced here:
http://surfer.nmr.mgh.harvard.edu/fswiki/eTIV To my knowledge, its relationship to the other aseg stats has not been explored, but maybe Bruce knows. Nick On Thu, 2007-12-06 at 11:10 -0800, Paul Greenberg wrote: > Hi All, > > I'm interested in the relationship between estimated total intracranial > volume (eTIV), and the volume measures generated in aseg.stats and > lh/rh.aparc.stats. I have used freesurfer v3.0.3 for this data set. > > Here I am using the output of aseg.stats for all volumes except the > cerebral cortex while using the output of aparc.stats exclusively for > estimates of cortical gray matter volume. As I'm looking at this data > for multiple subjects I've used asegstats2table and aparcstats2table to > extract the volume data for each subject (using the "--meas volume" flag). > > Question: > When I add these volumes generated in aseg.stats (excluding cortex), and > rh,lh aparc.stats (cerebral cortex only), should the total be very close > to the eTIV value found in aseg.stats? > > Thanks, > Paul > > _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
