Used primarily as a radiotracer in positron emission tomography (PET) imaging when labeled with fluorine-18. It helps visualize and measure glucose metabolism in tissues, particularly in cancer cells which exhibit high glucose uptake. Enables early detection of tumors, assessment of treatment response, and monitoring of disease progression. Also investigated for studying brain metabolism and neurological disorders due to its ability to cross the blood-brain barrier. Not metabolized beyond the initial phosphorylation step, trapping it inside cells and providing a stable signal for imaging.