Figure 15a. Medulloblastoma in a 37-year-old man with a 1-month history of progressively severe headaches and episodes of dizziness. (a) Axial T2-weighted MR image shows hyperintense cerebellar masses (arrows) within both hemispheres. (b) Contrast-enhanced axial T1-weighted MR image reveals mild enhancement of the right cerebellar mass and subtle enhancement of the left cerebellar mass.