Final answer:
PET scans use radiopharmaceuticals to reveal metabolic and physiological functions in tissues by collecting a radioactive isotope in the targeted area of the body.
Step-by-step explanation:
Positron Emission Tomography (PET) scans use radiopharmaceuticals to reveal metabolic and physiological functions in tissues. PET scans involve the use of a radioactive isotope that is either injected into a vein, swallowed, or inhaled. The isotope collects in the targeted area of the body, and the gamma ray emissions are detected by a PET scanner, which generates detailed images of the structure and function of various organs.