HI, I'm finishing a study I completed using an older version of freesurfer (20040218), and have noticed that I get different values for surface area and grey matter volume when using mris_anatomical_stats for my labels depending on whether I use the mris_anatomical_stats that it is part of this older distribution, or the one packaged as part of the newer dev release (20050905). I noticed on a previous posting that Doug Greve identified an error with respect to how surface area was calculated (I've included it below) and was wandering if this is the reason for the discrepancy. Should I believe the figures calculated using the newer version, or will this also be associated with errors, since the surfaces were generated using the older version? Thanks, Alex
I have just fixed a bug in FreeSurfer that involves computing the area > of some surface structures. For those of you who care, this was a bug > that emerged after converting our surface meshes from quadralaterals > to triangles. This change was made a few years ago. > > This change should have little effect on the reconstruction. It will > have an effect on programs that report the area of subsections of > cortex (but not total cortical area). At least three such programs > that are affected are: mris_compute_overlap, mris_label_area, and > mri_surfcluster. The bug causes the reported area to appear to be 1.5 > times what it really is. For example, in mri_surfcluster, a cluster > threshold of 300 mm^2 would actually be a threshold of 200 mm^2. > > For those in the NMR center, these three programs have been > updated. For those outside, you can get these programs from > > ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve > > New versions of freesurfer will, of course, have the update. > > Sorry for any inconvenience. > > doug > _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
