Corpus Callosum. A, Superior view of both hemispheres. The left and right cingulum have been removed to expose the body of the corpus callosum. Multiple transverse commissural fibers interconnect the paracentral and parietal regions of the hemispheres. B, Tractographic reconstruction of the body of the corpus callosum. The inset shows the color-coded DTI axial map used for the selection of the correspondent ROI (yellow). C, Anterior view, fiber dissection of the genu and rostrum of the corpus callosum. The genu contains the commissural fibers that connect the prefrontal and orbitofrontal regions to form the forceps minor. The lamina terminalis, which fills the interval between the optic chiasm and the rostrum of the corpus callosum, has been removed to expose the third ventricle. The upper part of the anterior wall of the third ventricle is hidden posterior to the rostrum of the corpus callosum. The columns of the fornix, which end in the mammillary bodies, and the anterior commissure form part of the anterior wall of the third ventricle. The diagonal band of Broca is identified coursing between the septal region and the amygdala. D, Tractographic reconstruction of the forceps minor of the corpus callosum. The inset shows the color-coded DTI axial map used for the selection of the correspondent ROI (yellow). E, Posterior view, fiber dissection of the splenium of the corpus callosum. The splenium contains the commissural fibers that connect the parieto-occipital and calcarine regions to form the forceps major, which courses under the cingulum. F, Tractographic reconstruction of the forceps major of the corpus callosum, formed by the commissural fibers passing through the splenium and interconnecting the parieto-occipital and calcarine regions. The inset shows the color-coded DTI axial map used for the selection of the correspondent ROI (yellow). (Images courtesy of E de Oliveira)