Cisterna magna

Dr Jeremy Jones et al.

The cisterna magna (also known as the cerebellomedullary cistern) is the largest of the subarachnoid cisterns.

The cisterna magna is located between the cerebellum and the dorsal surface of the medulla oblongata at and above the level of the foramen magnum. CSF produced in the ventricular system drains into the cisterna magna from the fourth ventricle via the median aperture (of Magendie) and the lateral apertures (of Luschka) 1-2.

Several vessels and nerves course through the lateral part of the cistern:

Antenatal ultrasound
  • cisterna magna normally measures between 2-10 mm in the second and third trimesters 4
CT/MRI
  • cisterna magna normally measures 3-8mm in the midsagittal plane when measured from the posterior margin of the foramen magnum to the caudal margin of the inferior vermis 3
Neuroanatomy
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Article information

rID: 5860
Section: Anatomy
Synonyms or Alternate Spellings:
  • Cerebellomedullary cistern

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Cases and figures

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    Figure 1: subarachnoid cistern
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    Figure 2: cisterns and CSF flow
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