Dec 30, 2025 · Mega cisterna magna refers to a normal variant characterized by a truly focal enlargement of the CSF -filled subarachnoid space in the inferior and posterior portions of the …

One of the supportive findings for the diagnosis of mega cisterna magna is the presence of internal lines crossing inside the cistern representing folds of the arachnoid membrane.

Focal enlargement of the CSF-filled subarachnoid space is seen in the posteroinferior portion of the posterior cranial fossa, consistent with mega cisterna magna, an anatomical variant.

Feb 12, 2025 · The cisterna magna (also known as the posterior cerebellomedullary cistern) is the largest of the CSF-filled subarachnoid cisterns.

Mega cisterna magna refers to a normal variant characterized by a truly focal enlargement of the CSF -filled subarachnoid space in the inferior and posterior portions of the posterior cranial fossa.

Mega cisterna magna is an incidental finding on neuroimaging, and no imaging follow-up is necessary. The presence of a normal posterior fossa and vermis distinguishes it from a Dandy-Walker …

Mega cisterna magna is an anatomic variant. Careful assessment of the cerebellar vermis and fourth ventricle is necessary to exclude cerebellar hypoplasia and a Dandy-Walker malformation.

Case Discussion Incidental mega cisterna magna. Images at higher levels confimed the presence of a normal posterior fossa and vermis distinguishing it from a Dandy-Walker malformation.

Incidental MRI findings are of mega cisterna magna. MRI was done for headache and limb weakness but was unremarkable for gross abnormality related to the mentioned complaint.

CT images illustrate enlarged cisterna magna without enlargement of the posterior fossa or vermian hypoplasia, findings suggest an incidental mega cisterna magna.