Positron Emission Tomography (PET)

Your Care Explained > Tests and Procedures : Positron Emission Tomography (PET)

Positron emission tomography (PET) is an imaging technology used in nuclear medicine to obtain pictures of the functional activity in areas of the body. It can detect areas of the heart that are not functioning properly and help doctors to determine whether tissue can recover if the blood supply is restored.

If you’re pregnant or are breast-feeding, let your physician know before you schedule a PET scan. Radiation can present some risks to the fetus, and the radionuclide contrast agent can be absorbed into breast milk.

What to Expect:

  • No food for 12 hours before the test.
  • The radioactive tracer may feel cool.
  • You will have to lie very still for 30 to 45 minutes.
  • The test will last 2 to 3 hours.
  • You’ll be able to go home on your own.

Because PET scanning “sees” chemical activity in tissues, it can help determine which heart tissue, if any, has permanent damage due to decreased blood flow. It may be used after a heart attack to determine which procedure, such as angioplasty or bypass surgery, may be most beneficial.

Preparing for a PET Exam

You will be asked not to eat anything for six to twelve hours and not to drink anything for one hour before the exam. Before the exam, a technician will explain the procedure and the slight risks associated with the test. You’ll read and sign a consent form acknowledging that you understand and accept the risks involved.

Your exam will take two to three hours. When you arrive at the imaging center, you will fill out a short registration form and be given a hospital identification bracelet. You will be asked to remove any jewelry you are wearing because it may interfere with imaging. The technician will give you a hospital gown to wear and take you to a dressing room to change.

Having a PET Exam

Before the test, the technician will insert an intravenous (IV) line into your arm or hand to deliver the FDG tracer—a radioactive substance that will reveal details of your heart on the scanner. You may feel a cool sensation as the tracer is injected. You’ll be helped to a padded table that will move slowly through the large ring of the PET scanner.

You will be asked to lie very still during the scan, which may last from 30 to 45 minutes. The technician will check the quality of the images to see whether additional images need to be taken. If not, you will be free to dress and leave.

Learning Your Results

A radiologist who is trained in evaluating PET scans will analyze the images of your heart and relay the information to your cardiologist, who will discuss them with you within a few days.

Date Last Modified: January 21, 2011

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