How does PET work?

PET stands for Positron Emission Tomography. PET scans measure metabolic activity and molecular function by using a radioactive glucose injection. The F-18 FDG is injected into the patient. The PET scanner detects the radiation emitted from the patient, and the computer generates three-dimensional images of tissue function or cell activity in the tissues of your body. These functional images can detect disease earlier than the anatomic information gained from CT alone. Like the CT scanner, your body will never come in contact with scanner itself. There are no side effects from this injection and procedure.

All cells use glucose as an energy source. However, cancer cells grow faster than normal healthy cells and they use glucose at much higher rate than normal cells. This is the basis of imaging with F-18 FDG for cancer detection in PET scan.