Brain positron emission tomography; PET scan - brain
A brain positron emission tomography (PET) scan is an imaging test that uses a radioactive substance (called a tracer) to look for disease or injury in the brain.
A PET scan requires a small amount of radioactive material (tracer). This tracer is given through a vein (IV), usually on the inside of your elbow. Or you may breathe in the radioactive material as a gas.
The tracer travels through your blood and collects in organs and tissues. The tracer helps the radiologist see certain areas or diseases more clearly.
You will need to wait nearby as the tracer is absorbed by your body. This usually takes about 1 hour.
Then, you will lie on a narrow table, which slides into a large tunnel-shaped scanner. The PET scanner detects signals from the tracer. A computer changes the results into 3-D pictures. The images are displayed on a monitor for your doctor to read.
You must lie still during test so that the machine can produce clear images of your brain. You may be asked to read or name letters if your memory is being tested.
The test takes between 30 minutes and 2 hours.
You may be asked not to eat anything for 4 - 6 hours before the scan. You will be able to drink water.
Tell your health care provider if:
Always tell your health care provider about the medicines you are taking, including those bought without a prescription. Sometimes, medications may interfere with the test results.
You may feel a sharp sting when the needle containing the tracer is placed into your vein.
A PET scan causes no pain. The table may be hard or cold, but you can request a blanket or pillow.
An intercom in the room allows you to speak to someone at any time.
There is no recovery time, unless you were given a medicine to relax.
A PET scan can reveal the size, shape, and function of the brain, so your doctor can make sure it is working as well as it should. It is most often used when other tests, such as MRI scan or CT scan, do not provide enough information.
This test can be used to:
Several PET scans may be taken to determine how well you are responding to treatment for cancer or another illness.
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Wahl RL. Imaging. In: Abeloff MD, Armitage JO, Niederhuber JE, Kastan MB, McKenna WG. Abeloff's Clinical Oncology. 4th ed. Philadelphia, Pa: Churchill Livingstone Elsevier;2008:chap 21.
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