Here is an explanation of etiv calculation in Freesurfer - https://surfer.nmr.mgh.harvard.edu/fswiki/recon-all
etiv is not obtained via direct segmentation of all structures within the skull boundaries. Rather, its estimation depends on the linear transform between the T1 image and a T1w atlas.
Best,
Yujing
From: freesurfer-bounces@nmr.mgh.harvard.edu freesurfer-bounces@nmr.mgh.harvard.edu On Behalf Of Carlos Alcocer Sent: Friday, January 5, 2024 4:11 PM To: Freesurfer support list freesurfer@nmr.mgh.harvard.edu Subject: [Freesurfer] poor inferior cerebellum segmentation
External Email - Use Caution Hello,
Inferior portion of cerebellum are not segmented well. It is included in skullstrip and I tried adding control points in cerebellar WM but this did not help. I am not interested in cerebellum but I do need eTIV. Will this poor cerebellar segmentation affect eTIV calculation?
Thank you,
Carlos