Mega cisterna magna

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Contents 1 Discussion of Mega cisterna magna 2 Imaging Findings for Mega cisterna magna 3 Images 4 See Also 5 External Links 6 References for Mega cisterna magna

[edit] Discussion of Mega cisterna magna

• The term mega cisterna magna has been loosely applied to a large retrocerebellar cerebrospinal fluid (CSF)–appearing space with a normal vermis and normal cerebellar hemispheres.
• More recently, the concept that a cisterna magna should enlarge only in response to volume loss of a damaged cerebellum has been revised. It is believed that when such large spaces manifest with mass effect on the cerebellum, enlargement of the posterior fossa and/or splitting of the falx, and supratentorial extension, they can be attributed not to an enlarged subarachnoid cistern but to a space-occupying lesion.

• Mega cisterna magna occurs in approximately 1% of all brains imaged postnatally.
• Mega cisterna magna has been associated with infarction, inflammation, and infection, particularly cytomegalovirus, as well as with chromosomal abnormalities, especially trisomy 18.
• In the absence of other findings to suggest a posterior fossa lesion, a mega cisterna magna is unlikely to be clinically significant.

[edit] Imaging Findings for Mega cisterna magna

• Prominent retrocerebellar cerebrospinal fluid (CSF)–appearing space with a normal vermis and normal cerebellar hemispheres.

[edit] Images

Patient #1

[edit] See Also

• Dandy-Walker malformation

[edit] External Links

• Goldminer: Mega cisterna magna

[edit] References for Mega cisterna magna

• Monica Epelman, Alan Daneman, Susan I. Blaser, Clara Ortiz-Neira, Osnat Konen, José Jarrín, and Oscar M. Navarro. Differential Diagnosis of Intracranial Cystic Lesions at Head US: Correlation with CT and MR Imaging. RadioGraphics 2006 26: 173-196.