The midsagittal section of the brain MRI with schematic illustration of landmarks and reference lines; FP, frontal pole; AC, commissura anterior; PC, commissura posterior; AGCC, the outermost point of corpus callosum genu; IGCC, innermost point of corpus callosum genu; TS, tuberculum sella, AGCC and IGCC points parallel to the AC-PC line and the point such a line crosses at the frontal lobe surface (FCS).