Pet scan how is it performed

This can help doctors decide on the most suitable treatment, and it can be useful if surgery is necessary. Cancer : PET scans can reveal the presence and stage of a cancer, show whether and where it has spread, and help doctors decide on treatment. A PET scan can give an idea of how well chemotherapy is working, and it can detect a recurring tumor sooner than other techniques.

Heart disease : A PET scan can help detect which parts of the heart have been damaged or scarred, and it can help identify circulation problems in the working of the heart. This information can help plan treatment options for heart disease. Medical research : Researchers can learn vital information by using PET scans, especially about the workings of the brain. A CT or MRI scan can assess the size and shape of body organs and tissue, but they cannot assess how these work.

Normally, the patient should not consume any food for at least 4 to 6 hours before the scan, but they should drink plenty of water. They may have to avoid caffeine for at least 24 hours before the scan. First, the doctor will inject a small amount of radiotracer into a vein. The tracer can also be breathed in as a gas, taken by mouth, or injected directly into an organ. Depending on which the organ is involved, it may take from 30 to 90 minutes for the radiotracer to reach the targeted part of the body.

Meanwhile, the patient will normally be asked to stay still and not talk. Some patients may be given medication to relax. When the patient is ready, they will be taken to a special room scan for the scan. They will lie down on a cushioned examination table. The most common use of PET is in the detection of cancer and the evaluation of cancer treatment.

To diagnose dementias conditions that involve deterioration of mental function , such as Alzheimer's disease, as well as other neurological conditions such as:. Parkinson's disease. A progressive disease of the nervous system in which a fine tremor, muscle weakness, and a peculiar type of gait are seen. Huntington's disease. A hereditary disease of the nervous system which causes increasing dementia, bizarre involuntary movements, and abnormal posture. To evaluate the perfusion blood flow to the myocardium heart muscle as an aid in determining the usefulness of a therapeutic procedure to improve blood flow to the myocardium.

To assist in the management and treatment of lung cancer by staging lesions and following the progress of lesions after treatment. White Marsh. PET scans can be done on an outpatient basis. It is also possible that some hospital inpatients may undergo a PET examination for certain conditions.

Although each facility may have specific protocols in place, generally, a PET scan procedure follows this process:. The patient will be asked to remove any clothing, jewelry, or other objects that may interfere with the scan. Certain types of scans of the abdomen or pelvis may require that a urinary catheter be inserted into the bladder to drain urine during the procedure. In some cases, an initial scan may be performed prior to the injection of the radionuclide, depending on the type of study being done.

The patient will be positioned on a padded table inside the scanner. Fasting for a certain period of time prior to the procedure is required, usually for at least four hours. You will be positioned on an examination table. An IV line will be inserted into your arm if needed. The radiotracer will then be injected into your vein, swallowed or inhaled depending on the imaging needed. You may have to drink a contrast liquid that helps the radiologist interpret the imaging results. The radiotracer takes about 30 to 60 minutes to concentrate in the organs.

During this time, you will be asked to lie still and not talk. You will be instructed to drink plenty of fluids and empty your bladder frequently for 24 to 48 hours after the test to help flush the remaining radionuclide from your body.

It helps detect cancers or areas of spread which have not been identified by other imaging studies such as a CT or MRI. The amount of the radionuclide used for the procedure is small enough that there is no need for precautions against radioactive exposure.

It can be done along with a CT scan. But you might also just hear it called a PET scan. Stage is a way to describe where the cancer is and if it has spread. Doctors also learn information about the stage if and how the cancer is affecting your body's functions.

Knowing the stage of cancer helps you and your doctor choose the best treatment. It also helps your doctor predict your chance of recovery. A CT scan shows detailed pictures of the organs and tissues inside your body. A PET scan can find abnormal activity and it can be more sensitive than other imaging tests. It may also show changes to your body sooner. Before your PET-CT scan, you will get an injection of a small amount of a radioactive sugar called fluorodeoxyglucose This substance is sometimes called FGD, radioactive glucose, or a tracer.

The cells in your body absorb sugar. Areas that use more energy pick up more of the sugar. Cancer cells tend to use more energy than healthy cells. The PET scan shows where the radioactive tracer is in your body. The CT scan takes x-rays of your body from different angles. You might get a shot of dye before the x-rays. This helps some of the details show up better. Your doctor gets a detailed 3-D result that shows anything abnormal, including tumors.

PET-CT scans do carry a risk of radiation. This type of scan uses some radiation from x-rays, the substance used in the PET scan, or both. Scanning a smaller body area means less radiation. So does a CT without the dye that helps show details. The benefits of these tests are usually greater than the risks. During these tests, you will be exposed to small amounts of radiation. This low dose of radiation has not been shown to cause harm.

For children or for other people who need multiple PET scans, CT scans, and x-rays, there may be a small potential increased risk of cancer in the future. Doctors can use lower dose scans or limit the areas that need to be scanned. Make sure all of your doctors know how many imaging scans you have had, including the number and type. This information can help them decide which scans to use in the future to help reduce your risk.

If you are concerned about your radiation exposure, talk with your doctor, including asking whether you can have another type of test that uses less radiation instead. After the test is done, a doctor who specializes in looking at the test results will look at your scan. This person is a nuclear medicine specialist or a radiologist.