FDG PET-MRI for the Diagnosis of Spinal Cord Lesions

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.

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

18FDG, FDG, Fludeoxyglucose (18F), fludeoxyglucose F 18, Fludeoxyglucose F18, Fluorine-18 2-Fluoro-2-deoxy-D-Glucose, Fluorodeoxyglucose F18

Magnetic Resonance Imaging Scan, Medical Imaging, Magnetic Resonance / Nuclear Magnetic Resonance, MR Imaging, MRI, MRI Scan, NMR Imaging, NMRI, nuclear magnetic resonance imaging

Medical Imaging, Positron Emission Tomography, PET, PET scan, Positron Emission Tomography Scan, Positron-Emission Tomography, proton magnetic resonance spectroscopic imaging

L is the lesion metric (mean, max, etc.) and B is the corresponding background metric. These values will be plotted versus time and the delayed time point corresponding to the highest value for each metric recorded. Differences in L/B ratio will be tested via paired t-test.

Defined as the time point by which there is the largest average SUVmax L/B ratio and significantly different from baseline at the 0.025 significance level.

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