Fig. 6. (A) MRI and (B) schematic image of the pituitary fossa and its anatomic relationships seen in coronal orientation. The cavernous sinus contains the internal carotid artery and cranial nerves III, IV, V1, V2, and VI. The optic chiasm resides immediately above the pituitary gland and is separated from it by a cerebrospinal fluid-filled cistern. (Modified from Lechan RM. Neuroendocrinology of Pituitary Hormone Regulation. Endocrinology and Metabolism Clinics 16:475-501, 1987.)