MRI - Medulloblastoma: An 8-year-old boy presented with the acute onset of headache, nausea, vomiting and ataxia. The T1-weighted MR image with contrast, seen on the left, reveals an enhancing midline lesion in the rostral cerebellum as well as multiple lesions in the left posterior temporal lobe, right anterior temporal lobe and along the mesial right temporal lobe near the peri-mesencephalic cistern. In the image on the right, several more lesions are seen in the right temporoparietal region. The multifocal appearance, especially along CSF surfaces, is consistent with this patient's diagnosis of medulloblastoma.