Acute hydrocephalus due to a cerebellar juvenile pilocytic astrocytoma.
This 4-year-old child presented with a 10-day history of headache, nausea, and vomiting. A. Contrast-enhanced sagittal MR shows an enhancing cystic and solid mass of the cerebellum. There is compression of the fourth ventricle. The cerebral aqueduct is prominent. B. There is mild dilation of the lateral and third ventricles on this coronal FLAIR image. Minimal periventricular edema is present.