Hi Glenn,

we have some estimated total intracranial volume (eTIV) in the new stuff using something that Randy Buckner showed recently - the determinant of the tal transform is predictive of TIV. Should be out soon. It's not clear however that thickness needs to be corrected by it. The MNI folks have shown in some cases that it does not, and thickness certainly doesn't scale with TIV linearly as many people have shown.

Bruce

On Thu, 8 Dec 2005, Glenn Lawyer wrote:

Bruce, I don't know how you manage to always get back to me so quickly, but I sure do appreciate it!

Yes, we were thinking of ICV. We are using the automatically generated surface labels and looking at the grey matter volumes.

Thanks again,

+glenn

Bruce Fischl wrote:

...

you mean by ICV? No, although in our new versions we compute ICV/TIV. Do you mean volume labels or surface labels? Volume of volume labels can be computed with mri_label_volume, surfaces can be given to mris_anatomical_stats -l <label name>

cheers, Bruce

On Thu, 8 Dec 2005, Glenn Lawyer wrote:

...

Hi,

We want to compare grey matter volumes from specific labels. Is the output of mris_anatomical_stats normalized in any way? It doesn't appear to be.

Thanks!

+glenn