What is mega cisterna magna and what is the outcome for a toddler? this showed up in my sons mri and i'm researching information.

Normal cong variant: Mega-cisterna magna,controversial entity among experts. In general non-pathological prominance (usually exceeding 10 mm in antenatal imaging) of the retro-cerebellar CSF space with normal vermis and normal cerebellar hemispheres.One study of adults showed normal cognitive function. I am 71 years and have had this anomaly. I am physician with no obvious neurologic or cognitive issues.

Don't worry: The Cisterna Magna is a collection of cerebrospinal fluid at the back of the brain between the two hemispheres of the cerebellum. The size of this normal fluid collection varies between people. A large one is called Mega Cisterna Magna or Giant Cisterna Magna. If accurately diagnosed, it is a normal variant, and causes NO PROBLEMS. Some other conditions can be confused with it.