Dear FreeSurfer experts,
After searching on FreeSurfer wiki and mailing list, I know that the ICV
reported in aseg.stats is an estimated value based on talairach
transformation. So, if the talairach transformation for a subject's head is
not good, the ICV for this subject is not accurate, am I right?
If this is the case, it may not be suitable to use ICV to adjust the
volumetric data in aseg.stats and ?h.aparc.stats for some special subjects.
I am thinking of using "brain volume" for this purpose. Here are the steps
to get it:
1. Get the surface-based volume of cerebral white matter (aseg.stats).
2. Add up the volumes of all cortical regions to get the surface-based
volume of cerebral cortex (aparc.stats).
3. Add up the above volumes (including both hemispheres) and the volumes of
all other regions listed in aseg.stats (except for cerebral white matter and
cerebral cortex) to get the brain volume.
Is this a suitable way to obtain more accurate brain volume?
Thanks in advance and any suggestions are greatly appreciated,
Xiangchuan Chen