CT Brain
There is a hyperdense mass arising from the roof of the 4th ventricle causing hydrocephalus. Following contrast, there is a heterogeneous enhancement of this posterior fossa mass.
No other lesions are seen in the posterior fossa or the cerebral hemispheres.
Features are those of a tumour with high cellularity arising from the roof of the fourth ventricle, and medulloblastoma should be highly considered. Cerebellar metastasis, choroid plexus papilloma, ependymoma are much less likely differentials.