Dear Freesurfer community, I wondered, how you correct the longitudinal hippocampus segmentation for total intracranial volume. Our cross-sectional analysis is corrected for total intracranial volume as described, for example, in Kerti et al. 2013 Neurology ( http://dx.doi.org/10.1212/01.wnl.0000435561.00234.ee ).
They used this formula: adjusted volume = raw volume - b*(ICV - mean ICV). The coefficient b represents the slope of regression of a region-of-interest volume on ICV. Now I am curious how to perform such a correction for intracraial volume for our longitudinal data. Do I correct for example the longitudinal hippocampus volume for timepoint 1, for eTIV found in SUBJECT.long.template/stats/aseg.stats, or for eTIV of the template, or anything else? Or are such corrections even neccessary for longitudinal runs? Thanks a lot for helping me out of my confusion. Best, Sebastian _______________________________________________ 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.
