How to Interpret PET Scans

Positron emission tomography (PET) is a non-invasive diagnostic imaging tool that is used to reveal how body tissues are functioning (unlike MRI or CT scans that reveal the structure of body parts and tissues). PET is mainly used for diagnosing cancer, heart diseases, seizures and dementia. The test uses a radioactive material that, depending on the organ or tissue examined, can be injected into a vein, inhaled or swallowed. Body tissues absorb this radioactive material (called tracer) at different rates, and a camera, the positron, detects the radiation coming from the body tissues creating three-dimensional images on a computer screen. A trained radiologist reads PET scans and writes a report explaining the findings.

Instructions

• 1

  Look for bright spots on your PET scan. Tissues and organs should show in a grey color in a PET scan. Areas of disease have higher chemical activities and thus absorb radioactive material faster and in larger quantities than tissues functioning normally. The radioactive material accumulating in the problem areas show up in bright colors and are referred to as 'hot spots."

• 2

  Know that "hot spots" can indicate different scenarios based on the area showing in the PET scan. Infections, growths, abnormal size or shape, and cancer appear brighter in a PET scan. Bright spots in a heart PET scan reveals abnormal heart function, while those in a brain PET scan can indicate Alzheimer's disease.

• 3

  Read the radiologist's report of your PET scan. The radiologist typically notes abnormalities in the PET scan and either gives a diagnosis if he or she knows enough information, or suggests further testing to diagnose the cause of the abnormal PET scan.

• 4

  Consult your doctor about any concerns that you have about your PET scan report. Realize that although PET scans are highly specific and sensitive, false positives can still occur, especially in diabetics where blood glucose or insulin levels can interfere with the radioactive material affecting test results.