Positron Emission Tomography, also called PET imaging or a PET scan, is a type of nuclear medicine imaging. Nuclear medicine imaging uses small amounts of radioactive material to diagnose or treat a variety of diseases. PET scanning is a very advanced tool used primarily to help detect cancer and Alzheimer’s disease, to localize the origin of epileptic seizures and to locate functional heart tissue prior to cardiac surgery.
With ordinary x-ray examinations, an image is made by passing x-rays through your body from an outside source. In contrast, PET uses a radioactive material called a radiopharmaceutical or radiotracer, which is injected into your bloodstream, swallowed or inhaled as a gas. This radioactive material accumulates in the organ or area of your body being examined, where it gives off a small amount of energy in the form of gamma rays. The PET scanner detects this energy and with the help of a computer creates pictures offering details on both the structure and function of organs and tissues in your body. PET evaluates the process, not the anatomy. It focuses on depicting physiologic processes within the body, such as rates of metabolism or levels of various other chemical activity, instead of showing anatomy and structure. Areas of greater intensity, called hot spots, indicate where large amounts of the radiotracer have accumulated and where there is a high level of chemical activity. Less intense areas, or cold spots, indicate a smaller concentration of radiotracer and less chemical activity.
The procedure will take about 2 to 3 hours altogether. We strongly suggest avoiding children and pregnant women for up to 10 hours after the PET procedure has been done. If you have any questions or concerns, do not hesitate to call our PET Schedulers at 425-952-6100. We are here to help you, so please feel free to contact us anytime.
PET Scan Instructions:
1. No strenuous activity the day before the exam.
2. Nothing to eat 6 hours prior to exam (Note: you may drink clear water only).
3. No vitamins on the morning of exam, but it is fine to take prescribed medications with water.
4. Please follow the high protein low carb diet 24 hours prior to date of exam.
5. Please ensure you drink at least 16 ounces of water one hour prior to the procedure.
6. If you are anxious and/or claustrophobic, please make arrangements with your doctor for medication, and arrange for a family member or friend to drive you home after the exam.
7. Refrain from wearing any metal (i.e. jewelry, barrettes, and any clothing with metal zippers or other metal adornments, sports bras are recommended for women).
8. Let your technologist know if you are pregnant or breast feeding.
9. If you are diabetic and your blood sugars run high, please arrange for medication adjustment with your doctor.
10. If you have had previous scans performed at other facilities, please bring these films or CDs with you to your appointment.
Because the doses of radiotracer administered are small, diagnostic nuclear medicine procedures result in low radiation exposure, acceptable for diagnostic exams.Thus, the radiation risk is very low compared with the potential benefits. Nuclear medicine diagnostic procedures have been used for more than five decades, and there are no known long-term adverse effects from such low-dose exposure. Allergic reactions to radiopharmaceuticals may occur, but are extremely rare and are usually mild. Nevertheless, you should inform the nuclear medicine personnel of any allergies you may have or other problems that may have occurred during a previous nuclear medicine exam. Injection of the radiotracer may cause slight pain and redness, which should rapidly resolve.
PET/CT scans are performed to:
- detect cancer
- determine whether a cancer has spread in the body
- assess the effectiveness of a treatment plan, such as cancer therapy
- determine if a cancer has returned after treatment
- determine blood flow to the heart muscle
- determine the effects of a heart attack, or myocardial infarction, on areas of the heart
- identify areas of the heart muscle that would benefit from a procedure
1. Please make sure you are scheduled for the earliest possible morning appointment.
2. Oral medications may be taken with water on the day of the exam, but please refrain from taking insulin.
3. Normal, "short-acting" insulin should be taken after the evening meal the night before your exam.
4. "Long-acting" insulin should be given as late as possible the evening before the exam, preferably as late as midnight.