Ambient cistern

Ambient Cistern

The ambient cistern or perimesencephalic cistern is a subarachnoid cistern located in the brain. It is a part of the ventricular system and is filled with cerebrospinal fluid (CSF).

Anatomy

The ambient cistern is situated laterally to the midbrain and contains the posterior cerebral artery and the superior cerebellar artery. It is bounded medially by the midbrain, laterally by the temporal lobe of the brain, and posteriorly by the tentorium cerebelli.

Function

The primary function of the ambient cistern, like other cisterns in the brain, is to act as a reservoir for cerebrospinal fluid. This fluid acts as a cushion for the brain, providing protection against injury. It also helps to remove waste products from the brain and supply nutrients to the brain tissue.

Clinical Significance

The ambient cistern is often evaluated in patients with subarachnoid hemorrhage (SAH). A blood clot in the ambient cistern on a computed tomography (CT) scan is a strong predictor of aneurysm rupture in the posterior circulation.

See Also

• Cistern (neuroanatomy)
• Cerebrospinal fluid
• Subarachnoid hemorrhage