I have several issues concerning automated volumes calculation. When you look at the aseg.stat for hippocampal volume (in mm3) it gives different value compared to hippocampal subfields volume calculation (which comes in voxels but there is stated that 1 voxel is 0.5mm3). How is it possible? I presume that anatomical definition and subfield incorporation is the same.

Next - if you look at the whole hippocampal formation volume in hippocampal subfield calculations it is way lower compared to the summation of the CA1-CA4 + dentate gyrus = hippocampal formation. What could be explanation of this?

Petr