PET is the acronym for Positron Emission Tomography. Positron emission tomography (PET) is a noninvasive test that assesses the level of metabolic activity and perfusion in various organ systems of the body. While many people think PET imaging is new technology, it has actually been available for about 25 years, used mostly in academic medical facilities throughout the United States and Europe.

To begin the procedure, a small amount of radioactive glucose is injected into the patient's bloodstream. There is no danger to the patient from this injection. Glucose (also know as sugar) is a common substance every cell in their body needs in order to function. Radioactive glucose must pass multiple quality control measures before it is used for any patient injection. The radiation exposure associated with PET is similar to that associated with a conventional CT scan.

After the injection, the patient will wait in a quiet room for about an hour, while the injected material is distributed throughout their body. Then, the patient will be asked to lie on a table that passes slowly through the scanner. The scanner resembles a CT scanner but is much quieter with only a handful of moving parts.

For their comfort and peace of mind, the patient should:

• Tell their doctor if the patient is:
  
  1. Pregnant
  2. Think's she is pregnant
  3. If she's a nursing mother
• Wear comfortable clothing.
• Tell the doctor if the patient is diabetic. Diabetic patients should take their insulin on the day of exam as normal
  
  If a diabetic patient's blood sugar is too high the examination will need to be rescheduled for a time when better blood glucose control is present.
• Wear their hearing aid, glasses or dentures to the PET center. However, they should leave valuables at home or in their patient room. Small security boxes will be provided.
• Take any prescribed medications on the day of their test unless instructed not to do so.
• Avoid all beverages with caffeine and sugar.

Depending upon the study, the patient may be required to fast after midnight prior to the exam. Also, most patients will be given a blood glucose test prior to injection to determine their blood glucose levels. Specific prep instructions will be provided when the patient is scheduled

The patient will be at the PET center for one and a half to three hours. The actual scan takes far less time.