At least five heterogeneous but predominantly T2 hyperintense and enhancing intra-axial lesions are present within the posterior fossa, the largest within the left inferior cerebellar hemisphere measuring 2.7 x 2.5 cm in transaxial diameter. 2 further punctate foci of enhancement in the right cerebellar hemisphere are suspicious for additional tiny lesions.
Most of these abut the pial surface and have enlarged supplying and draining vessels adjacent. Oedema and positive mass effect associated with the largest lesion, resulting in the distortion of the inferior mid brain, pons and fourth ventricle. Up to 13mm inferior tonsillar herniation. Moderated hydrocephalus with minor periventricular T2 hyperintensity. No further supratentorial abnormality, in particular no other intra-axial mass nor abnormal areas of enhancement.