What is by far the most likely diagnosis.
What is the most likely infective agent?
Streptococcus sp : 35 - 50%
Selected images from an MRI of the brain demonstrates a large peripherally enhancing mass in the right cerebellar hemisphere. It demonstrates prominent central restricted diffusion. It is surrounded by oedema and results in mass effect and compression of the 4th ventricle. A moderate degree of hydrocephalus is present (note the transependymal oedema).