Hi Jose
the threshold is set so that the EC label has the average surface area of the labels that went into the average. It is probably more accurate than the aparc as it is based on actual cytoarchitectural landmarks that are visible in ex vivo mri.
cheers Bruce
On Mon, 4 Feb 2019, Laboratorio de Neurociencia Funcional wrote:
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Dear Freesurfers,
gray matter volume of the entorhinal cortex (EC) can be obtained either in the ?h.aparc.stats or ?h.BA_exvivo.stats/?h.BA_exvivo.thresh.stats files. Considering that all our T1 images were manually edited on a slice-by-slice basis to correct pial surface misplacements and erroneous white matter segmentation, which volume measure of the EC would be more precise?
I assume that gray matter volume contained in ?h.BA_exvivo.thresh.stats were thresholded at a specific probability value (% of case overlapping). Which probability value was used? Is there a reference paper explaining how probabilistic maps of EC were built based on ex vivo MRI contrast?
Thank you in advance.
Best, Jose L. Cantero