Investigators are doing this study to determine which of four imaging techniques: Fludeoxyglucose Positron Emission Tomography (18 FDG PET) computerized tomography (CT), 18 FDG PET Magnetic resonance imaging (MRI), C-11 acetate PET CT, and C-11 acetate PET MRI) is the best test for finding sites of active myeloma disease.