It often allows for diagnostic information to be discovered long before medical problems are apparent with other diagnostic tests. What's more, this procedure provides detailed information that allows the physician to detect and treat a disease early in its course when there may be a more successful prognosis. Because a PET scan can detect sites of cancer not seen by other imaging modalities, it can be used to more effectively select patients who are likely to benefit from surgery. How PET Works Current diagnostic algorithms often fail to detect or identify disease in a wide variety of illnesses. A PET scan provides imaging with high sensitivity and specificity to improve these outcomes.
Many types of cancers have an increased use of glucose when compared to normal tissue.
Tissue that appears structurally similar on a CT scan or MRI, looks very different when FDG is used. A positron is a positively charged particle similar to its negative charged counterpart, an electron. When a PET agent releases a positron, it travels a short distance in tissue before combining with an electron. As it does, two packets of energy called photons are released at a 180 degree angle to each other. A special-purpose camera with two opposed detectors records the event, provided they occur within a narrow time window.