Hi all,<br><br>We want to normalize our data using eTIV and compared
the eTIV values generated in aseg.stats to the total brain volume we
calculate by summing:<br>1)&nbsp; Non-cerebral cortex volumes from aseg.stats (including ventricles)
<br>2)&nbsp; Cerebral cortex volumes from lh and rh.aparc.stats<br>We
compared&nbsp; eTIV to the total brain volume as calculated above from aseg
and aparc.stats for 40 subjects and found that, on average, eTIV is 27%
larger.&nbsp; This difference is larger than we expect.&nbsp; Are we missing
something?
<br><br>Thank you!<br>
<br><br>Jason