So the topology fix, spherical registration, etc. help the positioning for the random markov field algorithm?
And in the VBM we don't have this aid.
Is that correct?
2009/7/9, Bruce Fischl fischl@nmr.mgh.harvard.edu:
Hi PPJ
we don't use surface-based stuff for subcortical structures, although at some point we probably will. In general the surfaces are more accurate cortically as they let you do subvoxel positioning. I think the advantage for subcortical structures is that we have strong priors on both the intensity distributions and the spatial locations of structures such as putamen, pallidum, etc....
cheers, Bruce
On Thu, 9 Jul 2009, Pedro Paulo de Magalhães Oliveira Junior wrote:
It's more a methodological question, and I have asked this before, but I think it could be better discussed in the FreeSurfer community.
Several times people ask me what's the advantage of Surface based methods like the ones used in FreeSurfer over VBM in estimating volumetric parameters of subcortical structures.
The plain question people ask me is: what`s the advantage of FreeSurfer over SPM in terms of volumetric measures.
I have some answers for this. I have wrote something about in the FAQ of FreeSurfer but I was wondering if there's some comparative study or some better idea on this.
Pedro Paulo de M. Oliveira Junior Diretor de Operações Netfilter & SpeedComm Telecom --- Novo Netfilter 3.0 www.Netfilter.com.br --- Em breve Netfilter Small Business