Positron Emission Tomography (PET) Scan
Comprehensive Pain Specialists work with patients who are suffering from chronic pain. The goal is to help patients obtain relief from their pain so they can regain their ability to manage their lives. The first step is often diagnostic testing to determine the cause of the pain. Then, an appropriate health care plan and pain management regimen can be established. A PET scan is one test that may be used to identify the source of chronic pain.
A positron emission tomography scan, commonly referred to as a PET scan, is a unique imaging method that uses controlled radiation to diagnose abnormalities of the body’s functions. The scan is used primarily to show if organs and tissues in the body are functioning normally. Primary testing areas include the brain, breast, heart and lung. The test is used to:
- Measure blood flow, metabolism and oxygen use.
- Check on brain function.
- Identify and diagnose cancer.
- Determine whether cancer already identified has spread or recurred.
- Diagnose brain disorders.
- Identify areas with poor blood flow to the heart.
- Evaluate and detect neurological conditions.
- A PET scan is a noninvasive procedure with very few risks.
Patients may be asked not to eat or drink anything except water for four to six hours prior to the test. When they arrive at the testing area, prior to the test, they will receive an IV injection of radiotracer. Occasionally, the radiotracer may be given orally or by way of a gas that is inhaled.
It takes approximately one hour for the radiotracer to be absorbed in the body. It travels to and collects in areas of the body that may be diseased. These areas show up on the imaging as bright spots.
After the appropriate amount of time has passed, patients are asked to put on a hospital gown and empty their bladder. They then are placed on a moveable, padded examining table. Pillows and straps may be used to position the body and hold it in place.
The PET scan machine appears to be a huge doughnut. The test begins when the moveable examining table is slowly moved into the hole of the doughnut. The hole is large enough that the entire body of the patient is able to fit lengthwise into it. Patients are asked to hold very still throughout the testing process because any movement blurs the images and decreases the reliability of the images.
The test is monitored by a technician who sits in a booth just outside the testing room. Technicians and patients can communicate through a microphone and speaker. The technician can view the images as they are taken. Patients may occasionally be instructed to hold exceptionally still or to take a deep breath, hold it and then exhale.
The amount of time patients spend in the machine for the test is generally between 30 minutes and one hour depending on the body area that is being tested. Patients who have a fear of being in enclosed spaces need to tell their doctor or technician prior to the test. It may be possible for patients to be given medication to help them relax.
After the test is over, patients leave the facility. The radiotracer is eliminated from the body through the urine, so patients are told to drink a lot of water during the first few hours following the test in order to help with the elimination process. There is no recovery time except for those who were given medication to relax. Depending on the medication, patients may be asked to wait for a while before leaving or to have a friend or relative drive them home.
Review and report
The radiologist reviews the test results and forwards a report to the referring or pain management physician. The physician will discuss the result with the patient at a subsequent appointment.