All volumes. And area too as you note in #4External Email - Use Caution
Hello freesurfers,
I have some questions about the output variables of Freesurfer:
1. In the case of brain volume normalization, do I need to normalize all the volumetric results to the eTIV or just the subcortical volumes?
People will sometimes use eTIV as a regressor in the GLM instead of dividing (make sure to normalize so that the scale does not mess up the GLM)
2. Are there any formulas other than simple division in order to normalize the volumes?
standard deviation across vertices
3. How are the .ThckStd values (like FS_R_Insula_ThckStd) calculated? What does the "std" mean here?
I just use eTIV
4. I believe that the surface area outputs are also affected by brain size differences in the population. Are there any reference values in the Freesurfer outputs to which surface areas can be normalized?
Thank you in advance for your help.
Best regards,Yunus
--------------------------------------------------------------------------------Yunus SoleymaniPh.D. Candidate of NeuroimagingTehran University of Medical Sciences+98 914 526 9298--------------------------------------------------------------------------------
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