Patients scheduled to undergo gadolinium-enhanced MRI for urologic malignancy will be recruited to undergo PET/MRI employing simultaneous dynamic acquisition of PET and gadolinium-chelate data sets. For initial technical development within this pilot study, analysis will be performed attempting to compute tracer delivery using inputs from an integrated MRI-perfusion analysis. Flow and permeability will be obtained from the MR perfusion analysis, which can be used to compute the inflow rate constant K1. K1, reflecting the transfer of contrast, will then be used to compute the metabolic uptake of FDG by the organ as well as of any visible tumors. A determination will be made whether this metabolic uptake is successfully computed for each case. If not, then acquisition and post-processing modifications will be made for subsequent cases.
