Pilot Study of Safety and Toxicity of Acquiring Hyperpolarized Carbon-13 Imaging in Children With Brain Tumors

Inclusion Criteria: * Children ≥ 3 years and ≤ 18 years of age with a diagnosis of a brain tumor and who do not require sedation for MR imaging * Karnofsky ≥ 70 for patients ≥ 16 years of age, and Lansky ≥ 70 for patients \< 16 years of age (See Appendix 1 Performance Status Criteria) * Patients must not have any significant medical illnesses that in the investigator's opinion cannot be adequately controlled with appropriate therapy, would compromise the patient's ability to tolerate the imaging examination or any disease that will obscure toxicity or dangerously alter response to the imaging agent * Patients must not be pregnant or breast feeding. Women of childbearing potential are required to obtain a negative pregnancy test within 14 days of starting treatment. Effective contraception (men and women) must be used in subjects of child-bearing potential * Ability to understand and the willingness of the patient, parent or legal guardian to provide informed consent Exclusion Criteria: * Patients who are not able to comply with study and/or follow-up procedures * Patients receiving active therapy on an investigational trial at the time of enrollment should consult with the study chair regarding potential interactions with other study agents. Patients who are enrolled in a clinical trial but are off- therapy and in follow up are eligible. * Patients with history or evidence of cardiac dysfunction