What is a PET scan?

Positron Emission Tomography (PET) and Computed Tomography (CT) scans are both standard imaging tools that physicians use to pinpoint disease states in the body. A PET scan demonstrates how organs and tissues are functioning. This makes it an invaluable tool for diagnosis at a very early stage in a disease, often before structural changes take place. The CT scan provides information about the body's anatomy, such as size, shape and location. By combining these two scanning technologies, a PET/CT scan enables physicians to more accurately diagnose and identify cancer, heart disease and brain disorders.

How does a PET scan differ from CT or MRI scans?

CT and Magnetic Resonance Imaging (MRI) scans are anatomic imaging modalities, which means that they look at the size and shape of organs and body structures. Alternatively, A PET scan looks at how these organs and tissues are actually functioning. The information collected from a PET scan is different from any other test that is available.

Why is my doctor recommending a PET or PET/CT scan?

A single, painless PET or PET/CT exam can provide information that once would have required several medical studies and possibly surgery. PET scans are most often used to help the physician detect cancer and monitor response to treatment. PET scans are also used to evaluate heart disease and neurological conditions.

What are the benefits?

PET scans provide the physician with invaluable information. For cancer patients, it may help specialists understand the extent of disease, guide the most effective therapy, and then help evaluate if the treatment is effective. PET scans also aid in the diagnosis of heart disease and neurological diseases. This type of imaging may show changes much earlier than other imaging tests like CT or MRI.

Is PET safe?

The risks associated with a PET scan are very slight. The amount of radiation is low and the radiopharmaceutical decays quickly so there is no detectable radioactivity after a few hours. In addition to the radioactive decay, the remaining radiopharmaceutical is eliminated from the body through urine. Family members are not at risk for exposure since most of the radioactivity has left the body or decayed before the patient has left the center. The physician providing you with the PET scan will explain any associated risks and benefits from the PET or PET/CT exam.

What should I expect?

Upon arrival at the imaging center you will receive an injection of radiopharmaceutical, which will take approximately 30-90 minutes to be distributed throughout your body. You will be asked to empty your bladder and then to lie down on the scanner bed. The scan takes approximately 20-30 minutes, depending upon the type of scan you are having and the type of scanner that is being used. It is important that you lie still during this process. If you need pain medication, please bring it with you. You should plan on being at the imaging facility for approximately 2 to 3 hours.

What is a radiopharmaceutical?

Radiopharmaceuticals are used in a wide variety of Nuclear Medicine and PET exams to image and measure how the body functions. In PET imaging, the most commonly used radiopharmaceutical is a radioactive form of glucose. This allows doctors to image and measure how cells in the body use glucose for fuel. Different diseases increase or decrease the amount of glucose used.

What happens after my scan?

Once the PET scan is complete, you will be able to leave the imaging facility. Make sure you drink plenty of water or other fluids throughout the day to help flush the remaining radiopharmaceutical from your body.

Are there any potential side effects to a PET scan?

Ask the physician providing the scan to describe any potential side effects.

When will I get my results?

The PET scan is interpreted by a trained nuclear medicine physician or radiologist and results are usually sent to the referring physician within 24-48 hours. You should contact your doctor to discuss the results.

How often should I get a PET scan?

If you are under a physician's care, you should follow their recommendations for frequency of PET scans.

Are there alternatives to PET?

PET scans offer unique information about an organ's function that can show a physician signs of disease. 

Is a PET scan painless?

The only pain involved is the needle prick when you receive the radiopharmaceutical injection. This does not differ and is not more painful than any other type of injection.

Does my insurance cover PET scans?

Many PET scans are covered by private insurance and Medicare; pre-authorization may be needed and is advised. 

What can I do if I am claustrophobic?

PET scans can be difficult for some patients with claustrophobia. The tube of a PET scanner is not as tight and long as an MRI, but is slightly longer than that of a CT machine. The tube is open on both ends, and the room has a very large window with a view of trees. Most patients have no issue with it.

Below are some techniques that we have found helpful in reducing some of the anxiety associated with claustrophobia:

• Talk to us beforehand: Fear about scans and claustrophobia are relatively common. By making us aware of your apprehension early on, we can work together to create a plan to reduce your distress and improve the experience.

• Listen to music: It’s astounding how much of a difference the use of music can make to reduce stress in an anxiety-provoking situation. We can play calming music that will allow your mind and body to relax. Alternatively, you can choose your favorite tunes that give you comfort. We are happy to play them for you!

• Focus on breathing: Focused attention on deep, slow breathing can create a physiological and psychological response that relaxes both the body and the mind. Using mindful meditation skills as part of your PET scan can also be a helpful strategy.

• Cover your eyes as soon as you lay down on the table, before the table moves: It may seem like this is an overly simplistic suggestion, but sometimes a simple act can make a huge difference when it comes to managing anxiety. Consider guiding yourself through some calming imagery. Conjure a peaceful scene and then imagine the details in your mind’s eye. Imagine you are lying on the beach, or wherever you feel most at ease. You might be surprised at how relaxing this exercise can be!

• Bring a friend for support: Inviting a friend to support you during the scan can be a soothing and healthy distraction from the task at hand. If you are reluctant to ask, remember that you may be asked to reciprocate someday and that your friend would probably be glad to help.

• Count: The use of counting as a distraction technique is simple, easy and practical. Focusing on the numbers will shift the focus away from any stress associated with the procedure. If you want an even more complex distraction, work on some math problems in your head!

• For some patients with strong worries about the scan, it can be helpful to visit us a few days prior to the actual scan and do a “dry run”, becoming familiar with the environment and with lying on the table.

• Ask for sedation: Many mild medications can be taken before procedures. Short-acting sedative drugs such as the benzodiazepines Xanax, Ativan, or Valium may be an option to discuss with your doctor if your claustrophobia is severe. If so, medication should be taken prior to the start of the exam and in accordance with your doctor's instructions.

Claustrophobia is relatively common, particularly with imaging tests such as MRI, CT and PET scans that involve enclosed spaces. Simple management techniques can help make the experience much less stressful.

Regardless of what claustrophobia management techniques you use, don’t hesitate to share your thoughts and feelings with your referring physician, with Dr. Riedl, and with the technician at ImagingWest prior to having your PET scan done.