Altered signal intensity lesion measuring 34 x 33 x 41 mm (AP x TD x CC) in posterior fossa. The lesion is completely occupying the fourth ventricle, distending it. It is extruding out of right foramen of Luschka and reaching up to right internal auditory canal. It is compressing medulla anteriorly and right cerebellar hemisphere posteriorly. Areas of haemorrhage /calcification seen with heterogeneous enhancement on post contrast study.
Right vertebral artery is seen in close proximity to the lesion.
No obvious evidence of hydrocephalus is seen in present scan.