In FluoroDeoxyGlucose, a radiotracer (radiopharmaceutical) is injected into the bloodstream. __ uses glucose at a much higher rate than normal cells

• A. Normal cells
• B. Cancer
• C. Infected tissue
• D. Bones

Answer: (B)

FDG PET imaging relies on how much glucose cells are using. Cancer cells typically consume much more glucose than normal cells because they rely heavily on glycolysis, even when oxygen is available. This elevated glucose use means they take up more FluoroDeoxyGlucose and trap it inside, since FDG is phosphorylated but not further metabolized, leading to strong signals on the scan. Normal cells use glucose at baseline levels, so their FDG uptake is comparatively lower. Infected tissue can show increased uptake due to inflammation, but not to the same sustained, high level as cancer. Bones don’t inherently have the high, abnormal glucose metabolism characteristic of malignant tissue. So the bright, high uptake of FDG best identifies cancerous tissue.