zystische Kleinhirntumoren

Role of

diffusion-weighted imaging in differentiation between posterior fossa brain tumors. Epidermoid cyst in 38-year-old male complaining from auditory problems. A lobulated extra-axial cystic lesion is seen in the right cerebellopontine angle (CPA) insinuating itself, compressing the pons, extending into prepontine cistern, and encasing the basilar artery. It displays low T1WI signal intensity (a) and high T2WI signal intensity cerebrospinal fluid (CSF) like (b). On FLAIR, it shows low SI (partially suppressed SI (c). It shows faint marginal enhancement on post-contrast study (d). It shows iso SI-like brain parenchyma (restricted diffusion); it does not have high CSF SI-like arachnoid cyst (e)

School ager

with double vision. Axial CT with contrast of the brain shows a large heterogeneous cystic and solid mass encompassing the entire right cerebellar hemisphere which is compressing the slit-like fourth ventricle and shifting it to the left, resulting in obstructive hydrocephalus of the third and lateral ventricles.The diagnosis was cerebellar astrocytoma.

Cerebellar

pilocytic astrocytoma: MR spectroscopy. T2WI shows hyperintense lesion in posterior fossa with effaced 4th ventricle and triventricular hydrocephalus with eccenteric intermediate signal intensity solid component.

Hemangioblastoma

of cerebellum

Magnetic

resonance imaging of pineal region tumours. Arachnoid cyst in a 27-year-old woman with headache and dizziness. Sagittal T2-weighted image (a) demonstrates a cystic infratentorial lesion (arrow) in the pineal recess, which has high signal. On coronal FLAIR image (b), the lesion (arrow) has isointense signal relative to CSF