Inclusion Criteria

- INCLUSION CRITERIA:

1. Age: greater than or equal to 1 years and less than or equal to 21 years.

2. Radiographic diagnosis: Patients must have a brain tumor (including, but not
limited to high grade gliomas, low-grade gliomas, primitive neuroectodermal
tumors, ependymomas) or residual abnormality (e.g. post-operatively or
post-radiation) that is measurable or evaluable on standard MRI or CT.

3. All patients or their legal guardians (if the patient is less than 18 years of
age) must sign a document of informed consent indicating their awareness of the
investigational nature and the risks of this study. When appropriate, the minor
patient will be asked for oral assent. The parent or guardian will sign the
consent form on the designated line attesting to the fact that the minor has
given assent.

4. Durable Power of Attorney (DPA): A DPA will be offered to all patients 18-21
years of age.

5. Prior treatment: Patients will be eligible for this study regardless of prior
treatment, as long as they meet other eligibility criteria. Therefore, patients
who are newly diagnosed, post-operative, post-radiation or post-chemotherapy are
eligible.

EXCLUSION CRITERIA:

1. Patients under age 18 years who weigh greater than 70 kg are excluded because they
would exceed the standard allowable dosimetry for pediatric patients (i.e. Effective
Dose greater than 0.5 REM/year). In addition, patients who weigh greater than 136 kg
are excluded, as this is the maximum weight allowable on PET scanner tables.

2. Pregnant women are excluded because the effects from the magnet on the fetus are
unknown. In addition, gadolinium is not approved for use in pregnant women, because
its teratogenic effects have not been studied and we wish to avoid radiation exposure
to the fetus.

3. Any patient who is unable (either because of physical or psychological factors) to
undergo imaging studies without sedation but is not considered an anesthesia
candidate.

4. Any patient with a metallic MRI incompatible implant, including cardiac pacemakers,
neural pacemakers, aneurysmal clips, shrapnel, cochlear implants or ferrous surgical
clips.

5. Any patient with a history of a severe reaction (CTC v.4 Grade greater than or equal
to 2) to Gadolinium or other contrast agents.

6. Any patient with Diabetes mellitus or steroid-induced hyperglycemia (fasting glucose
greater than 150) because this may interfere with the interpretation of the
[(18)F]-FDG PET scan.

7. Any patient with permanent braces, permanent retainers or nonferrous implant that, in
the judgment of the Principal Investigator, would interfere with obtaining
spectroscopy in the area of the tumor.