Reason: History of medulloblastoma treated with surgery, chemotherapy, and radiotherapy, has cochlear implant that is MRI compatible to 1.5 tesla. See note from 8/13/2015 Emmanuel J Villegas, A.P.N. for instructions History: yearly follow up There is again extensive susceptibility artifact from a right cochlear implant, obscuring large parts of the right posterior head/intracranial structures. This includes the cerebellar treatment bed at midline in the posterior fossa. There is minimal central nodular enhancement along the inferior cerebellum as seen on 12/34, which appears similar if not slightly less conspicuous when compared to prior exams. Minimal linear enhancement is seen along the right anterior aspect of the overlying fluid collection, presumably relating to granulation tissue. Otherwise, the visualized brain demonstrates no abnormal contrast enhancement. T2/FLAIR hyperintense gliosis is again seen along the left paramedian frontal lobe with adjacent chronic lacunar infarct in the corona radiata the left. Ventricles and sulci remain prominent, consistent with moderate global volume loss greater than expected for patient's stated age. Diffusion weighted imaging is essentially nondiagnostic. There is no midline shift or mass effect. There is a persistent small extracranial CSF signal intensity collection along the suboccipital craniectomy site, consistent with a pseudomeningocele. This measures 1.7 cm AP x 7.1 cm CC, not significantly changed.
1. Limited exam secondary to extensive susceptibility artifact from right-sided cochlear implant. Incomplete visualization of the surgical bed in the posterior fossa, although no definite suspicious enhancement identified to suggest tumor recurrence.2. Grossly stable appearance of presumed pseudomeningocele overlying the craniectomy site