What is a PET Scan?

PET stands for “positron emission tomography”. It is a nuclear medicine imaging test in which a small amount of liquid radioactive material is injected into your body and is used to diagnose a variety of diseases, including many types of cancers, heart disease and other diseases. 
  • The radioactive substance most commonly used in PET scanning is a simple sugar (like glucose) called FDG, which stands for “fluorodeoxyglucose”.
  • It is injected into your bloodstream and accumulates in your body where it gives off energy in the form of gamma rays. 
  • These are detected by the PET scanner and a computer converts the signals into detailed pictures or images showing how tissue and organs are working.
  • If you are having an FDG PET, your sugar metabolism (how sugar is used by your body) is imaged. 
  • This is commonly used for cancer imaging as tumours need sugar to grow.

When is a PET scan used?

PET scanners are now commonly combined with computed tomography (CT) scanners, called PET-CT scanners. CT imaging uses X-ray equipment to create detailed images of slices of the inside of your body. The PET-CT combination allows any abnormality on the PET scan to be precisely located within the body, allowing for more accurate diagnosis of any problems. The PET or PET-CT scanner looks like a large box with a circular hole in the middle.

Watch our PET-CT video to learn more about what to expect. 

We know you probably have questions about your upcoming PET test. This video will help ease your trepidation about the procedure and hopefully answer any questions you may have.

If there are any questions you still have please call us at 478-633-4PET. (478-633-4738)
What happens during a PET scan procedure?
  • After you arrive at the office, a nurse or technologist will explain the procedure and prepare you for the PET scan. 
  • You will be asked to change into a gown. 
  • A small needle will be inserted into a vein, usually in your arm or the back of your hand, to fit an intravenous line (a thin plastic tube) through which the liquid radioactive material is injected. 
  • A brief medical history will be taken to ensure the optimal (or best) scanning method is used and to also help with subsequent image interpretation. 
  • Your blood sugar level will be checked, as high or low blood sugar levels can alter the appearance of the scan. 
  • The radioactive substance is then injected into your vein through the intravenous line.

  • If you are having an FDG PET scan, you will be asked to rest quietly in a bed or arm chair, avoiding movement or talking for 90 minutes. 
  • During this time you will be alone as there is limited room for visitors, and it will prevent your friends or relatives from receiving unnecessary radiation exposure.
  •  You may be asked to drink some contrast material that moves through your stomach and bowel and helps to improve the interpretation of the scan. 
  • Occasionally, depending on the medical indication (symptom or condition), a catheter (a thin flexible tube) may be placed into your bladder to help improve image quality.

  • You will then be moved to the scanning room and positioned on the PET scanning bed.
  • It is important to remain as still as possible during the scan as movement can result in reduced image quality and the images may be blurry.
  •  Therefore, if you are uncomfortable after being positioned on the bed please tell the technologist.

If you are having a PET-CT, the CT scan is performed first and takes less than 2 minutes. The PET scan takes approximately 30 minutes but the time will vary depending on the regions of your body being scanned.

The intravenous line will be removed before you leave.

What are the risks of a PET scan?

Some people experience claustrophobia (fear of being confined in a small space) when inside the scanner machine. If you have experienced claustrophobia in the past, please inform your doctors's office prior to the exam or inform the technologist, nurse or doctor, as they can take steps to minimize your feeling of claustrophobia.

Occasionally, other drugs will be given as part of a PET scan and any possible side effects will be discussed with you.

What are the benefits of a PET scan?

Nuclear medicine procedures, including PET scanning, are very safe. 
  • The scan involves an injection of a very small amount of a radioactive material or tracer, which will only remain in your body for a few hours. 
  • It gives you a small amount of additional radiation but does not cause any side effects. 
  • The radiation dose you receive is equivalent to several years of natural background radiation from the normal environment.

If there is any possibility that you are pregnant or if you are breastfeeding you should inform the nurse, technologist or doctor.

Make sure you are prepared.

  • No food, gum, cough drops or mints for six (6) hours before your exam. Avoid caffeine, sugar, tobacco and heavy exercise for 48 hours before your exam.

  • Drink lots of water.

  • Please take all regular medication before your exam, unless otherwise directed.

  • If you are diabetic, call 478-633-4738, please contact the office in advance for instructions.

  • If you suffer from claustrophobia, please call your doctor. 

You will receive an injected, oral or inhaled preparation of an isotope (a radioactive material) before your exam. This material highlights the part of your body being examined and allows the radiologist to see how certain organs are functioning.

What you should bring:

  •     Prescription or referral from your physician.
  •     List of medications you take, including non-prescription medications and supplements.
  •     Insurance cards and picture id
  •     Any previous, relevant imaging exams and reports performed outside of our network.
  •     Medical history, including whether you may be pregnant or breastfeeding currently.
  •     Pathology reports.

For more details on your specific exam or if you have ANY questions, please call our scheduling department at 478-633-4PET.

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