Fig 2.

Regional measurements. A, Biparietal width (BPW) and interhemispheric distance (IHD) are measured on a single coronal section by use of the cochlea and basilar truncus as landmarks. B, Callosal thickness is measured on a midsagittal view at 3 different regions: the genu, the midportion, and the splenium. C, Ventricular diameters (VDs) and transcerebellar diameter (TCD) are measured on a coronal view at the level of the ventricular atrium. D, The deep GM area (DGMA) is measured on a single axial section at the level at which the caudate heads, the lentiform nuclei, and the thalami are maximally visible.