The pituitary gland is a pea sized structure in the middle of your brain just behind your eyes. It sits inside a bone cavity called the sella dorsica. The gland is attached to the brain by a thin stalk called the infundibulum.  Pituitary gland MRIs are used to discover tumors of the pituitary gland, such as microadenomas, craniopharyngiomas, apoplexy tumors, and cysts.