this is for holding javascript data
Anisha Keshavan added Freesurfer_uses_an_atlas_scaling__.tex
over 8 years ago
Commit id: f660969532def1dadcbd24da8bcea936e307b257
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Freesurfer uses an atlas scaling factor (ASF) to calculate the eTIV, so even though the ROI encompasses all others, it is not calculated in the same way as other ROIs (i.e. by counting the voxels inside the skull). Rather, it estimates a linear transformation to an atlas space (Talairach) and calculates the determinant of the transformation matrix, which correlates to ICV \cite{buckner2004unified}. So actually the mechanism behind the biases in eTIV are different than those behind other regional volumes (i.e. regional varaition in CNR and gradient distortions affect the boundary). \textbf{Should I remove eTIV from the table then?}
