Explore chapters on Dandy Walker Complex and Megacisterna Magna.
Dandy-Walker Complex
Under this term are included a group of conditions that share in common one sonographic findings: the impression that the fourth ventricle communicates with the cisterna magna. These conditions include: Dandy-Walker malformation, Blake’s pouch cyst, vermian hypoplasia/agenesis. They have a similar sonographic appearance, particularly in early gestation, and differentiation requires a multiplanar approach.
Megacisterna Magna
Enlarged (> 10 mm) cisterma magna with a normal cerebellum. It may be associated with other anomalies, including trisomy 18 and other cerebral malformations. When isolated, fetal mega cisterna magna has a good chance of intrauterine remission, and is usually (> 90%of cases) associated with a good outcome.
Retrocerebellar space enlargement: Mega Cisterna Magna and Arachnoid Cyst
The cisterna magna (CM, aka cerebellomedullary cistern) is the largest opening in the extracerebral space, positioned between the arachnoid and the pia mater meninges.