Inclusion Criteria

Inclusion Criteria (Aim 1):

- Subjects must be 13 years of age or older.

- Subjects (or their parent or legal guardian) must have signed Internal Review Board
(IRB)-approved assent/informed consent documentation.

- Subjects must have histologically proven osteogenic sarcoma, or malignant fibrous
histiocytoma (MFH), of the pelvic or long bones.

- Subjects must be planned for resection, this includes localized resectable disease or
patients with metastatic disease with planned palliative resection, and scheduled to
begin neoadjuvant chemotherapy

Exclusion Criteria (Aim 1):

- Subjects who are under 13 years of age.

- Subjects who have any type of bioimplant activated by mechanical, electronic, or
magnetic means (e.g., cochlear implants, pacemakers, neurostimulators,
biostimulators, electronic infusion pumps, etc), because such devices may be
displaced or malfunction.

- Subjects who have any type of ferromagnetic bioimplant that could potentially be
displaced.

- Subjects who have cerebral aneurysm clips.

- Subjects who may have shrapnel imbedded in their bodies (such as from war wounds),
metal workers and machinists (potential for metallic fragments in or near the eyes).

- Subjects with inadequate renal function (creatinine ≥1.5 times upper limit of
normal)or acute or chronic renal insufficiency (estimated glomerular filtration rate
<30 mL/min).

- Subjects who are pregnant or breast feeding, because the effects of high field MRI on
fetuses are not yet known. Urine pregnancy test/or serum human chorionic gonadotropin
(HCG) will also be performed on women of child bearing potential.

- Subjects who have exhibited past allergic or other adverse reactions in response to
intravenous injection of Magnevist® (gadopentetate dimeglumine) or other
gadolinium-containing contrast agents.

- Subjects who exhibit noticeable anxiety and/or claustrophobia or who exhibit severe
vertigo when they are moved into the magnet bore.

Subjects incapable of giving informed written consent, for the following reasons:

- Inability to adhere to the experimental protocols for any reason

- Inability to communicate with the research team

- Limited ability to give informed consent due to mental disability, altered mental
status, confusion, or psychiatric disorders

- Prisoners or other individuals deemed to be susceptible to coercion

Inclusion Criteria (Aim 2):

- Subjects must be 18 years of age or older.

- Subjects must have signed IRB-approved informed consent documentation.

- Subjects must have histologically proven osteogenic sarcoma, or malignant fibrous
histiocytoma (MFH), of the pelvic or long bones.

- Subjects must be planned for resection, this includes localized resectable disease or
patients with metastatic disease with planned palliative resection, and scheduled to
begin neoadjuvant chemotherapy.

Exclusion Criteria (Aim 2)

- Subjects who are under 18 years of age.

- Subjects who are pregnant or breast feeding, because the effects of radiotracers and
other contrast media used in PET/CT on fetuses are not yet known. Urine pregnancy
test/or serum human chorionic gonadotropin (HCG) will also be performed on women of
child bearing potential.

Subjects who have experienced allergic or other adverse reactions in response to
intravenous injection of fluorinated radiotracers or other PET/CT contrast media.

-Subjects incapable of giving informed written consent, for the following reasons:

- Inability to adhere to the experimental protocols for any reason

- Inability to communicate with the research team

- Limited ability to give informed consent due to mental disability, altered mental
status, confusion, or psychiatric disorders

- Prisoners or other individuals deemed to be susceptible to coercion