Greetings,

I have two questions regarding FS volume measurements.

I intend to use the volume information of .stats files but I got some doubts regarding the methods used.

1) I read that eTIV estimation is based on the TAL transformation, but what about the volumes of cortical and subcortical areas? Is it a simple voxel count?

 2) In some studies the authors normalize the volumes to eTIV. In others the authors don't do any normalization. Some of them use it as co-variate. What's your opinion regarding this matter? 

Thank you in advance!

Best regards,