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Pontocerebellar cistern

The pontocerebellar cistern, also known as Hilton’s cistern, is a prominent subarachnoid space located at the ventral aspect of the pons, situated between the pons and the anterior surfaces of the cerebellum. It forms part of the wider basal cistern system and communicates with adjacent cisterns, including the prepontine and cerebellopontine angle cisterns. This cistern serves as a crucial conduit for cerebrospinal fluid (CSF) flow, surrounds important neurovascular structures such as the basilar artery, and accommodates several cranial nerves, especially cranial nerves VI, VII, and VIII. Its anatomical boundaries and contents are critical in both diagnostic neuroradiology and surgical approaches to the posterior fossa.

Synonyms

  • Hilton’s cistern

  • Lateral pontine cistern

  • Lateral cerebellopontine cistern (in some contexts, although this term can also refer to the cerebellopontine angle cistern)

Function

  • Acts as a reservoir and conduit for cerebrospinal fluid (CSF) between the prepontine cistern and the cerebellopontine cisterns.

  • Cushions and protects the adjacent brainstem (pons) and cerebellum.

  • Contains and protects vital neurovascular structures:

    • Basilar artery and its branches.

    • Cranial nerves VI (abducens), VII (facial), and VIII (vestibulocochlear) as they pass to/from the brainstem.

  • Serves as an important anatomical landmark in neuroimaging and neurosurgery.

MRI Appearance

  • T1-weighted images:

    • CSF within the cistern appears hypointense (dark).

    • Cranial nerves and vessels may be visualized as slightly hyperintense (gray) structures within the cistern, depending on resolution.

    • The margins of the cistern are well-defined by the pons anteriorly and the cerebellum posteriorly.

  • T2-weighted images:

    • CSF appears hyperintense (bright), making the cistern easily distinguishable.

    • Cranial nerves appear as dark (hypointense) linear or dot-like structures coursing through the bright CSF.

    • Adjacent brainstem and cerebellar tissue show intermediate to low signal intensity.

  • FLAIR (Fluid Attenuated Inversion Recovery):

    • CSF signal is suppressed (dark/hypointense), making the cistern appear dark.

    • Abnormalities such as blood or proteinaceous material within the cistern can appear hyperintense (bright).

    • Useful in identifying pathology that alters CSF signal.

CT Appearance

  • On non-contrast CT:

    • CSF within the pontocerebellar cistern appears as hypodense (dark) areas.

    • The cistern is identified as a clear space anterior to the cerebellum and posterior to the pons.

    • Basilar artery and cranial nerves are typically not visualized unless calcified or with contrast.

    • Acute blood within the cistern (e.g., subarachnoid hemorrhage) appears hyperdense (bright).

MRI images

Pontocerebellar cistern (Hilton) mri 3t sagittal image

CT image

Pontocerebellar cistern CT sag anatomy image -img-00001-00001