To compare the results and understand the possible benefits from FDG-PET/MRI during different scanning time points after FDG, a type of contrast drug, is given.

Primary Objectives:

--To identify the optimal imaging time point using F18-FDG positron emission tomography (PET) that gives the best lesion conspicuity as defined by the best lesion to background (L/B) ratio when evaluating spinal cord lesions of unknown etiology.

Exploratory Objectives:

• To identify malignancy specific factors in F18-FDG metabolism derived from metrics such as maximum standard uptake value (SUVmax), mean standard uptake value (SUVmean), total lesion glycolysis (TLG), metabolic tumor volume (MTV) and L/B ratio.
• To identify patterns of metabolism derived from metrics such as SUVmax, SUVmean, TLG, MTV, L/B ratio and magnetic resonance imaging metrics such as regional perfusion abnormalities, apparent diffusion coefficient values and mean diffusivity measures.

OUTLINE:

Patients receive fludeoxyglucose F-18 intravenously (IV) over 1 minutes and then undergo PET-magnetic resonance imaging (MRI) over 15-60 minutes at 60, 300, and 480 minutes after fludeoxyglucose F-18 injection in the absence of unacceptable toxicity.

Inclusion Criteria:

• Patients with untreated intramedullary cord lesion(s)
• Ability to undergo FDG PET MR examination

Exclusion Criteria:

• No prior surgery or biopsy of the spinal cord
• No metal implanted in area of interest
• Spine radiation therapy
• Known allergy to FDG or gadolinium based contrast agents
• Blood glucose (> 200 mg/dl)
• Pregnant women are excluded
• Children of less than 18 years of age
• Need for conscious sedation or anesthesia in order to tolerate study