Hi, Nothing in the stats is normalized. It makes sense to normalize volumes by ICV when comparing across subjects (as that is assumed to stay constant while GM volume of course changes ).
Not sure if aseg...table grabs it, it should, maybe Krish knows.
Best Martin
On May 17, 2011, at 8:19 AM, Fernanda Palhano nandapalhano@gmail.com wrote:
Hello,
I have two questions about volumetric analysis: First: Are the volume measures in the files aseg.stats or ?h.aparc.stats (Gray Matter Volume) already normalized by ICV? Or should I divide all the structure volumes which I want to compare between subjects by the ICV of each subject? Second: When comparing gray matter volumes the correct is use the ICV or the total cortical gray matter volume to normalize? And if I have to use the total cortical gray matter volume, how can I obtain it? I know that this information is in the aseg.stats file, but I was wondering if I can use asegstats2table to extract it.
Thank you very much,
Fernanda
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