A PET scan is done by injecting a small amount of radioactive material (known as a tracer) into a patient's vein, usually in the arm. The tracer sends out small, positively charged particles (positrons) that interact with negatively charged particles (electrons) in your body. The PET scanner is able to detect the product of this interaction and uses it to make an image. The PET scan shows the brain's use of oxygen or sugar (glucose).
A seizure originating in the temporal lobe of the brain may be preceded by an aura or warning symptom, such as:
Abnormal sensations (which may include a rising or "funny" feeling under your breast bone or in the area of your stomach)
Hallucinations (including sights, smells, tastes)
Vivid deja vu (a sense of familiarity) or recalled memories or emotions
A sudden, intense emotion not related to anything happening at the time
During the seizure, a person may experience motor disturbances,...
For patients with epilepsy, a PET scan is used to localize the part of the brain that is causing the seizure activity.
However, doctors may request a PET scan for many different reasons. Aside from potential problems in the brain and spinal cord, the test can also be used to diagnose heart problems as well as certain kinds of cancer, including breast, brain, lung, colon, and prostate cancers and lymphoma.
How Do I Prepare for a PET Scan?
Before undergoing the PET procedure, be sure to tell your doctor of any medication -- prescription or non-prescription -- that you are taking, along with any herbal drugs or supplements you may be using. It is also very important that you tell the doctor if you are pregnant or think you may be pregnant, since the PET scan can be harmful to an unborn child.
As the test is about to begin, you will be asked to take off clothing that is covering the area of the body to be tested. Depending on the area of your body being tested, you may be asked to undress completely and put on a hospital gown. You will also be asked to remove any dentures, jewelry, or metal objects during the scan, because these items may affect the reading.