Therefore, a PET image may provide earlier detection before there is any obvious structure present. It often allows for diagnostic information to be discovered long before medical problems are apparent with other diagnostic tests. PET is especially useful for detecting and staging cancer, differentiating scar tissue from tumor and benign from malignant lesions. To help the radiologist or nuclear physician see the PET image, it is necessary to inject the patient with a tracer that aids in visualization. FDG is an analog of glucose.
Many types of cancers have a very high affinity for glucose when compared to normal tissue.
A special PET camera is then used to take an image of the patient who received the FDG to see how the body processes the drug. In the image, the abnormal tissue will be highlighted which assists the physician to interpret the extent of disease. This procedure provides detailed information that allows the physician to detect and treat a disease early in its course. 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. In the past, PET has been used as a powerful research tool in medical schools and universities only.