Positron Emission Tomography and CT Imaging

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What is PET/CT?

A positron emission tomography (PET) scan is an imaging test that uses a small, safe amount of a radioactive substance to look for disease. A computed tomography (CT or CAT) scan uses x-rays to quickly create cross-sectional images. These methods are used together in a PET/CT scan to create three-dimensional pictures of your body.

A PET/CT scan is often used to diagnose cancer and brain disorders. Several scans may be taken over time to determine how well a patient is responding to treatment.

What can I expect?

A small amount of a radioactive material will be injected into one of your veins, usually on the inside of your elbow. You'll be asked to wait quietly as it's absorbed, which usually takes about an hour.

Legacy is committed to keeping radiation exposure to our patients as low as possible - the "As Low As Reasonably Achievable" standard, and by being an active participant in the American College of Radiology Image Gently and Image Wisely programs.

Then you'll lie on a table that slides into a tunnel-shaped hole in the center of the PET scanner. The scanner detects energy from the radioactive substance and changes it into 3-dimensional images. The length of the test depends on what part of your body is being scanned.


How will it feel?

We will do everything we can to make you as comfortable as possible. You may feel discomfort from the needle stick, but the scan itself is painless, but you must lie still so that we can get the sharpest images.

How should I prepare?

  • You'll be asked not to eat anything for 4 - 6 hours before the scan, but you will be able to drink water.
  • Tell your health care provider about any prescription and over-the-counter medicines you are taking, because they may interfere with the test. Talk to your doctor if you take any blood thinners that would affect bleeding (Coumadin/Warfarin, Pradaxa).
  • Be sure to tell your health care provider if you have any allergies, or if you've had any recent imaging studies using injected dye (contrast).
  • Tell the imaging staff if you are or might be pregnant.
  • You'll be asked to take off any jewelry, dentures, and other metal objects that could affect the scan results.
  • You may be asked to wear a hospital gown.

More information 

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