Re: [Freesurfer] aseg.stats - eTIV volume space

[Wighton, Paul]

Hi Katie,

FreeSurfer operates mostly in "FreeSurfer Space", which is voxel resolution of 
1mm^3 and sagittal orientation.

You can compare orig.mgz to the original input to see what the difference 
between native space and FreeSurfer Space would be.

eTIV is computed using the transformation matrix from FreeSurfer Space to 
MNI305 space.  There is more information here about it here:
https://surfer.nmr.mgh.harvard.edu/fswiki/eTIV

-Paul


From: freesurfer-boun...@nmr.mgh.harvard.edu 
 on behalf of Katie Rose Jobson 

Sent: Thursday, June 23, 2022 6:08 PM
To: freesurfer@nmr.mgh.harvard.edu 
Subject: [Freesurfer] aseg.stats - eTIV volume space


External Email - Use Caution

Hi FreeSurfer experts,

I apologize if this question has been addressed, but I was unable to find a 
definitive answer elsewhere.

I am using the aseg.stats file to extract the estimated Total Intracranial 
Volume (eTIV) value to be used as a correction to my anatomical data. I just 
want to confirm what space this data is in. I had previously assumed this data 
was in native anatomical space. But I read on the wiki that this statistic is 
calculated using the Talairach transform file (talairach.xfm), which is the 
conversion from MNI305 to Talairach. I just want to ensure I am correct in the 
assumption that this data is represented in native anatomical space.

Thank you so much for your help in this matter.

Best Wishes,
Katie

--
Katie Jobson, M.S.
PhD Student | Cognitive Neuroscience 
Lab<https://secure-web.cisco.com/15mzkkYt-HVv32ujlEOwH-7Z0bKXddWNX6mHpHztqONWIef5bhXdtvwaqeCMAqXHV4m6rr9FTXR0PdLkBaebCNtkqJdlDdUWe9Q_S9hdsGhx1v4P-OpFyduzf1UCVUgynaahq9WCAWd90ZY4iBgZ_Hq_JHbLXJhDJquBe9on-jfDhjz-fs6tHjSz0Zv4oh1gEhFQ_Qf7BnaGC-eQvOLtweSCHRmBLLN2CDX1yIRzO-7Z8pcNS6YLJKCrJvMvrvlgASKbJuGaluqeVrpj3dPumnAXN55tFeo9HqZbVtDBT3FGwjnpF-w6Brx02SzFSS-HS0ySfOjnJRbqcfZam0r5oDg/https%3A%2F%2Fsites.temple.edu%2Fcnltu%2F>
Department of Psychology and Neuroscience | Temple University
[cid:dcfe96a7-bf68-4d92-8c1e-61f5814893fa]
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[Freesurfer] aseg.stats - eTIV volume space

[Katie Rose Jobson]

External Email - Use Caution

Hi FreeSurfer experts,

I apologize if this question has been addressed, but I was unable to find a 
definitive answer elsewhere.

I am using the aseg.stats file to extract the estimated Total Intracranial 
Volume (eTIV) value to be used as a correction to my anatomical data. I just 
want to confirm what space this data is in. I had previously assumed this data 
was in native anatomical space. But I read on the wiki that this statistic is 
calculated using the Talairach transform file (talairach.xfm), which is the 
conversion from MNI305 to Talairach. I just want to ensure I am correct in the 
assumption that this data is represented in native anatomical space.

Thank you so much for your help in this matter.

Best Wishes,
Katie

--
Katie Jobson, M.S.
PhD Student | Cognitive Neuroscience 
Lab
Department of Psychology and Neuroscience | Temple University
[cid:dcfe96a7-bf68-4d92-8c1e-61f5814893fa]
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The information in this e-mail is intended only for the person to whom it is 
addressed.  If you believe this e-mail was sent to you in error and the e-mail 
contains patient information, please contact the Mass General Brigham 
Compliance HelpLine at https://www.massgeneralbrigham.org/complianceline 
 .
Please note that this e-mail is not secure (encrypted).  If you do not wish to 
continue communication over unencrypted e-mail, please notify the sender of 
this message immediately.  Continuing to send or respond to e-mail after 
receiving this message means you understand and accept this risk and wish to 
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