Combined PET/CT scans can be performed on any part of the body. They are frequently used to gather information about the heart, brain, and lungs.
PET scans use a radioactive form of sugar (or other molecules) to measure the cellular activity of the body part being scanned. A CT scan takes a large number of x-rays. These are analyzed by a computer to create a three-dimensional image of the body part being studied. When both tests are performed at the same time, the information about function and structure is integrated through computer models.
Because combined PET/CT scans provide a combination of information about the function and structure of a body part, they are very useful for the early diagnosis of cancer. Not only can the presence of an abnormal tumor be noted, but the function of the cells that make up the tumor can be analyzed. This can help to differentiate between benign growths (not cancer) and malignant growths (cancer).
PET/CT is also used in re-staging previously diagnosed cancer.
Each of these tests has its own limitations. When combined, they provide very precise information on
location and activity. In the past, both of the tests had to be done separately, making the interpretation of results more difficult due to changes in the patient’s body position. However, with the availability of scanners that combine both technologies, this is no longer a problem. Many cancer specialists believe that this technology will allow doctors to reduce the number of invasive procedures that patients need to undergo (eg,
biopsies) and still be able to provide very accurate monitoring.
Brain and heart disorders are also studied using PET/CT scans.
Some possible complications with this test include:
Allergic reactions to the chemicals used
What to Expect
Prior to Test
Prepare a list of medicines you are taking; bring the list with you to the test.
If you have
diabetes, discuss taking your diabetic medicines and/or insulin with your doctor prior to the test. An abnormal blood glucose level may interfere with the tests results.
If instructed to do so by your doctor:
Eat a high-protein, low-carbohydrate diet for the day or so prior to your test.
Drink about 3-4 glasses of water prior to arrival for your test.
Do not to eat for 6-8 hours prior to your test.
Inform the staff performing the test if you:
Ever had a reaction to a contrast agent or iodine in the past
Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a