Chiasmatic cistern

The chiasmatic cistern or suprasellar cistern is a small subarachnoid cistern related to the optic chiasm.

Anatomy
The cistern is situated superior to the optic chiasm, and inferior to the rostrum of corpus callosum. 

The cistern is an extension of /communicates inferiorly with the interpeduncular cistern. The cistern of lamina terminalis connects the chiasmatic cistern with the pericallosal cistern.

Contents
It contains the anterior aspect of the optic chiasm and both optic nerves (CN II), the pituitary stalk, the origin of the anterior cerebral artery, and the anterior communicating artery.