A large right retro-cerebellar extra-axial cyst is seen compressing the right cerebellar hemisphere and elevating the tentorium being insinuated between the occipital lobes. It is seen following CSF signal on all sequences with facilitated diffusion. It is seen measuring 3.2X7.7X6.5 cm along its axial and cranio-caudal dimensions.
Annotated image showing the membrane of the arachnoid cyst (red arrows). Remodelling of the skull is also present (blue arrow head).