The landmarks to identify the correct slice on the midline sagittal slice were: (i) a distinct outline of the CC; (ii) no white matter or only minimal white matter in the cortical mantle surrounding the CC; (iii) the interthalamic
adhesion; and (iv) a transparent septum and visibility of the aqueduct of Sylvius.
They fund that width anterior to the interthalamic adhesion has no statistical significance and posterior is significant among 6-9 years.
A point on the right lateral wall of the third ventricle and another identical point on the left lateral wall on thalamus is used to measure width posterior to interthalamic adhesion.
Concerning differences, strong interthalamic
adhesions in the brain of the spider monkey were found, a cerebral structure which usually is very slim in the human.