Dear Freesurfer experts, I have a question about eTIV (FS 5.3) which I use as a covariate where appropriate. Is it in some way influenced by the presence of brain atrophy? I have a new sample of subjects in a longitudinal study: at time 1 they have some atrophy (due to low body weight) that improves in time 2 (4 months). I observed that eTIV-time1 is slightly correlated with weight (r=0.3) whereas no correlation is present at time 2. The correlation between eTIV-time1 and eTIV-time2 is somewhat lower than expected (r=0.53) and is lower than correlation between SegBrain_Vol_1 and SegBrain_Vol_2 (0.65).
Do you suggest in these cases to perform manual segmentation to obtain TIV? or is there any other method (in freesurfer) to obtain an estimate of TIV not influenced by brain atrophy? What about using BrainMask_to_TIV? Thank you for any suggestion Angela _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer 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 Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.
