A radioconjugate containing the D-galactose analogue 2-deoxy-2-fluoro-D-glucose (FDGal) labeled with the positron-emitting radioactive isotope fluorine F18, used for imaging upon positron emitting tomography (PET). With cell uptake much higher in tumor cells compared to normal cells, the F18 moiety of fluorodeoxygalactose F-18 can be visualized upon PET imaging and this agent can be used as a tracer for the evaluation of galactose tumor uptake and metabolism.