CSF, Ventricles & Brain Anatomy

Basal cisterns

The basal cisterns are wider pools of cerebrospinal fluid at the base of the brain within the subarachnoid space.

In short: Basal cisterns

  • They are enlarged pools of CSF at the base of the brain.
  • They are part of the CSF circulation pathway.
  • An ETV opening connects the third ventricle to one of these cisterns.
  • They are assessed on imaging.

What it is

The basal cisterns are larger, pool-like expansions of the subarachnoid space located at the base of the brain. They hold CSF and are part of the pathway through which fluid circulates around the brain.

Understanding Basal cisterns

As CSF exits the ventricular system, it passes through the basal cisterns at the base of the brain on its way to circulate and be absorbed. These cisterns are important in surgery: an endoscopic third ventriculostomy (ETV) creates an opening from the floor of the third ventricle into a basal cistern (the interpeduncular cistern), allowing CSF to bypass a blockage. The cisterns are also assessed on imaging, since bleeding or infection within them can impair CSF circulation.

Why it matters

Understanding the basal cisterns helps families see how an ETV works — by connecting the ventricle to one of these CSF pools — and how problems in the cisterns can affect CSF circulation.

Common questions

What are the basal cisterns?

Wider pools of CSF at the base of the brain.

How are they relevant to ETV?

An ETV opening connects the third ventricle to one of these cisterns.

Are they assessed on imaging?

Yes.

Bottom line

The basal cisterns are CSF pools at the base of the brain, important in CSF circulation and as the target of an ETV opening.

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