Inclusion Criteria:

- Adults must have either radiological or established histological diagnosis of the
following general categories: high-grade glioma/CNS lymphoma or brain metastases from
lung or breast cancer.

- Previously untreated patients must have a lesion on an imaging study

- Post treatment patients will have radiographic abnormalities that may or may not be
recurrent tumor

- If a patient needs a biopsy or neurosurgical procedure for diagnostic and/or
therapeutic purposes as necessary treatment for their disease, the scans will be
assessed and the tissue assessed by histology and/or EM for iron particles. Only
clinically indicated biopsy and/or surgery will be done and surgery is incidental to
inclusion in the protocol.

- Patients must be 18 years or older for inclusion in this study.

- Patients may have had prior therapy for the primary brain tumor, including
radiotherapy or chemotherapy.

- For those patients with metastatic disease previous therapy of the primary tumor is
permitted.

- After entry into the study, patients are expected to be followed for approximately
4-6 weeks after the final infusion of ferumoxytol.

- All patients, or their legal guardians, must sign a written informed consent and
HIPAA authorization in accordance with institutional guidelines.

- Sexually active women of child-bearing potential and men must agree to use adequate
contraception (hormonal or barrier method of birth control; or abstinence) prior to
study treatment and for the duration of study treatment. Should a female become
pregnant or suspect she is pregnant while participating in this study, she should
inform her treating physician immediately.

- Pre-treatment radiological scans/studies for patients receiving ferumoxytol must be
performed approximately 4-6 weeks prior to study entry.

Exclusion Criteria:

- Patients with clinically significant signs of uncal herniation, such as acute
pupillary enlargement, rapidly developing motor changes (over hours), or rapidly
decreasing level of consciousness

- Patients with known allergic or hypersensitivity reactions to parenteral iron,
parenteral dextran, parenteral iron-dextran, or parenteral iron-polysaccharide
preparations (Ferumoxytol Investigator's Drug Brochure, 2009). Patients with
significant drug or other allergies or autoimmune diseases may be enrolled at the
investigator's discretion.

- Patients who are pregnant or lactating or who suspect they might be pregnant.

- Adult patients who require monitored anesthesia for MRI scanning

- Patients with stage IV (GFR 15-29 mL/min/1.73 m2) or stage V (GFR <15 mL/min/1.73 m2)
renal insufficiency.

- Subjects who have a contraindication for MRI: metal in their bodies (a cardiac
pacemaker or other incompatible device), are severely agitated, or have an allergy to
Gd contrast material.

- Subjects with known hepatic insufficiency or cirrhosis.

- HIV-positive patients on combination antiretroviral therapy are ineligible because of
the potential for pharmacokinetic interactions with ferumoxytol.

- Subjects with known or suspected iron overload (genetic hemochromatosis or history of
multiple transfusions).