Just a thought, but I suspect that the volume is calculated as some product of area * "thickness". Then, with the -t option, what FS is using as thickness is now really the lgi value. So, the "volume" value is really not appropriate in that case.
cheers, Mike H. On Fri, 2008-05-09 at 15:28 +0200, Marie Schaer wrote: > On my understanding, the GM volume given by mris_anatomical_stats > should be the same independently of the -t option (unless you > reprocessed the surfaces in between), so that's surprising. > > Doug, do you have any idea? > > Marie > > > On 9 mai 08, at 15:12, Martin Kavec wrote: > > > Thanks a lot for clarification, Marie. > > > > On Friday 09 May 2008 14:37:46 Marie Schaer wrote: > >> Martin, > >> > >> As lgi is read like a thickness file, the lgi values in your tabular > >> output replaced the value where you had thickness before. So mean lgi > >> is in column 4 (note that average lgi values per parcell are > >> comprised between 1 and 5 if your lgi computation is ok). Standard > >> deviation for lgi is in column 5. The other columns should not change > >> if you run mris_anatomical_stats without the -t option (i.e on the > >> thickness). > > > > Well, the point is that the 3rd column (not counting the structure > > name) is > > changed as well. This corresponds to GM volume, which is (almost) > > systematically larger in the lh.lgi.stats. Should it really be the > > same? This > > is already off my questions, but I am just saying that as a feedback. > > > > Thanks a lot, > > > > Martin > > _______________________________________________ > 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
