The use of magnetic resonance imaging in the evaluation of retinoblastoma.

We examined a 4-year-old boy who had a painful blind eye, rubeosis iridis, and leukokoria. Ultrasonography and computed tomography (CT) detected intraocular calcification and other features suggestive of retinoblastoma. The CT scan showed extraocular extension along the optic nerve. Intracranial extension of the tumor could not be definitely excluded by CT scan with intrathecal metrizamide infusion. Magnetic resonance imaging (MRI) and CT performed after radiation and chemotherapy were useful in excluding intracranial spread of malignant cells, thereby aiding the selection of a surgical approach to ensure complete removal of the involved portion of the optic nerve.