29 years, Male, history of medulloblastoma and VP shunt. Evaluate for leukoencephalopathy.. There are extensive areas of FLAIR hyperintensity in the subcortical and bilateral periventricular white matter in the bilateral cerebral hemispheres. Small lacunar infarcts are also seen in the right greater than left basal ganglia. There is moderate degree of global parenchymal volume loss, particularly in the left cerebral hemisphere including encephalomalacia in the left temporal lobe. There is ex vacuo dilatation of the lateral ventricles left greater than right. There is a right transfrontal VP shunt catheter with the tip in the right frontal horn. There is no evidence of hydrocephalus. There is no restricted diffusion to suggest acute ischemia. There are multiple foci of susceptibility effect in the bilateral cerebral hemispheres consistent with chronic microhemorrhages and likely related to prior treatment. There is T1 hyperintensity involving the bilateral basal ganglia and the dentate nuclei within the cerebellum which may be related to prior radiation.There is T2/FLAIR hyperintensity involving the bilateral cerebellum and to a lesser degree in the pons. Areas of cystic change are noted in the right cerebellar hemisphere which may related to prior tumor. There is no abnormal parenchymal or meningeal enhancement in the posterior fossa or elsewhere in the brain to suggest tumor recurrence.Major flow-voids are preserved. There is mild mucosal thickening throughout the paranasal sinuses. The sphenoid sinus is under pneumatized. Extensive T1 hyperintensity involving the skull base is compatible with prior radiation.
1. Extensive areas of white matter signal abnormality particularly supratentorially are compatible with leukoencephalopathy related to prior chemoradiation. 2. There is parenchymal volume loss, particularly in the left cerebral hemisphere including encephalomalacia in the left temporal lobe.3. Multifocal areas of susceptibility effect compatible with chronic microhemorrhages and/or mineralization also likely related to prior treatment.4. No findings to suggest tumor recurrence.