Hi Martin,
1. FS uses geometry to do inter-subject registration, which in our experience results in a much better matching of homologous cortical regions than volumetric techniques.
2. FS allows you to look at the two components of volume separately (thickness and surface area). We have found that these two do not necessarily track one another, and in the worst case where one is increasing and the other decreasing the volume change can be 0.
3. The target we use for registration (the white matter surface geometry) is completely invariant to gm atrophy, so gm changes won't results in a different registration.
Steve Smith and Morgan Hough at Oxford just did a pretty comprehensive study of this, so maybe they will chime in.
cheers, Bruce
On Wed, 14 May 2008, Martin Kavec wrote:
Gentlemen,
I am giving a lecture about aging brain. I only discuss freesurfer, since that's the method we use for the brain volume and cortical thickness assessment. There are other methods, such as VBM and SIENA potentially providing similar information. I would appreciate if you could point me to a reference, which compares features of Freesurfer and VBM, or if you could provide me your insight on what are the advantages of FreeSurfer over VBM.
I could think of the following:
Freesurfer allowes for the subvoxel precision of the volume estimation
VBM involves strong filtering in order to suppress variations of individual
anatomies
????
????
????
Thanks a lot in advance.
Martin _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer