Hi Jessica,
I don't think this is normal. Is this a single subject? Of course in a single subject lots of stuff can go wrong. Are the surfaces correct? And the hippo label? Are there motion artifacts in the image etc.
Anyway, you should process this with the longitudinal stream: http://freesurfer.net/fswiki/LongitudinalProcessing which should increase repeatability.
Best, Martin
On Wed, 2011-07-27 at 09:01 -0700, Jessica Liu wrote:
Hi,
We found 20% differences in temporal lobe brain volume and ca. 5% difference in the hippocampus volume between two data sets of a young normal volunteer scanned 2 days apart.
We use the one-step 19 hours recon-all -all procedure and directly sum select values taken from the lh.aparc.stats, rh.aparc.stats, and wmparc.stats. The values summed were based on information given from https://mail.nmr.mgh.harvard.edu/pipermail/freesurfer/2007-April/005000.html
My question is, are these observations normal for Freesurfer? Any comments are greatly appreciated. Thanks! -- Pom & Jessica
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