PET Scan Safety

Positron emission tomography, also referred to as a PET scan or PET imaging, is a way to get images of the body via radioactive emissions. These scans are commonly used to detect cancer or the spread of a cancer, determine whether the heart is getting enough blood, and to map brain function. Radioactivity worries many people, but PET scans are actually quite safe.

Function

• A PET scan requires you to ingest or apply a radiotracer--a substance containing a minute amount of radioactive materials. You may swallow it as a pill, have it injected, inhale it as a gas or apply it like an ointment. The tracer will eventually accumulate in the part of your body that needs to be scanned. Then doctors use a gamma camera and a PET scanner to detect emissions from the tracer and get a clear image.

Benefits

• PET scans provide more information than other methods of imaging, including X-rays, CT scans and ultrasounds. A PET scan can tell doctors about important bodily functions, including how your body is using sugar, whether certain parts of the body are getting enough oxygen, and whether you have normal blood flow. When combined with CT scans and MRI information, PET scans can lead to very precise diagnoses.

Considerations

• Some people should not receive PET scans. Pregnant women or women who are breast feeding may need to delay their scan or take precautions suggested by their doctors. Some people have mild reactions to radiopharmaceuticals, so medical personnel will ask about any existing allergies you have and any problems you've had during other PET scans.

History

• According to the Radiological Society of North America, PET imaging has been used for over 50 years. During this period, no patients have shown long term adverse effects from the very low dosage of radioactive material used in scanning. This type of scan is becoming more popular as an alternative to exploratory surgery, since it poses lower levels of risk. Patients do not need anesthesia before undergoing a PET scan.

Potential

• Since PET scans identify changes in the body at a cellular level, they can show early onset disease before an MRI or CT scan can detect it. These scans are also safer, more precise, and less costly than exploratory surgery, and can detect the success or failure of cancer treatments in the short term.

Warning

• PET scanning can produce a false result in some patients if their body's chemical balance is abnormal. Patients who eat shortly before having their scan, diabetic patients and late arrivals may all have trouble getting an accurate scan. Some people who are very obese may not be able to get a PET scan due to the opening size on conventional PET units.