A positron emission tomography (PET) scan is an imaging test that uses a radioactive substance (called a tracer) to look for disease in the body.
Unlike magnetic resonance imaging (MRI) and computed tomography (CT) scans, which reveal the structure of and blood flow to and from organs, a PET scan shows how organs and tissues are working.
See also:
Alternative NamesNuclear medicine scan; Positron emission tomography
How the test is performedThe health care provider will inject a small amount of a radioactive material into one of your veins, usually on the inside of the elbow. The substance travels through the blood and collects in organs and tissues.
You'll be asked to wait nearby as the radioactive substance is absorbed by your body. This usually takes about 1 hour.
Then, you will lie down on a table that slides into a tunnel-shaped hole in the center of the PET scanner.
The PET machine detects energy given off by the radioactive substance and changes it into 3-dimensional pictures. The images are sent to a computer, where they are displayed on a monitor for the health care provider to read.
You must lie still during the PET scan so that the machine can produce clear images. How long the test takes depends on what part of the body is being scanned.
How to prepare for the testYou must sign a consent form before having this test. You will be told not to eat anything for 4 - 6 hours before the PET scan, although you will be able to drink water.
Tell your health care provider if you are pregnant or think you might be pregnant.
Also tell your health care provider about any prescription and over-the-counter medicines that you are taking, because they may interfere with the test.
Be sure to mention if you have any Allergies, or if you've had any recent imaging studies using injected dye (contrast).
During the test, you may need to wear a hospital gown. Take off any jewelry, dentures, and other metal objects because they could affect the scan results.
How the test will feelYou will feel a sharp prick when the needle with the radioactive substance is inserted into your vein. You shouldn't feel anything during the actual PET scan.
Why the test is performedA PET scan can reveal the size, shape, position, and some function of organs.
This test can be used to:
Several PET scans may be taken over time to determine how well you are responding to treatment for cancer or another illness.
Normal ValuesThere are no problems detected in the size, shape, or position of an organ. There are no areas in which the radiotracer has abnormally collected.
What abnormal results meanThe amount of radiation used in a PET scan is low. It is about the same amount of radiation as in most CT scans. Also, the radiation doesn't last for very long in your body.
However, women who are pregnant or are breastfeeding should let their doctor know before having this test. Infants and babies developing in the womb are more sensitive to the effects of radiation because their organs are still growing.
It is possible, although very unlikely, to have an allergic reaction to the radioactive subtance. Some people have pain, redness, or swelling at the injection site.
Special considerationsIt is possible to have false results on a PET scan. Blood sugar or insulin levels may affect the test results in people with Diabetes.
Most PET scans are now performed along with a CT scan. This combination scan is called a PET/CT.
ReferencesBeller GA, Kramer CM. Nuclear cardiology and computed tomography. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 54.
Ettinger DS. Lung cancer and other pulmonary neoplasms. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 201.
Hackney D. Radiologic imaging procedures. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 419.
A positron emission tomography (PET) scan is an imaging test that uses a radioactive substance called a tracer to look for disease in the body.
Unlike magnetic resonance imaging (MRI) and computed tomography (CT), which reveal the structure of and blood flow to and from organs, a PET scan shows how organs and tissues are working.
See also:
Alternative NamesPositron emission tomography
How the test is performedA 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. It 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. Too much movement can blur images and cause errors.
How long the test takes depends on what part of the body is being scanned.
How to prepare for the testYou 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.
How the test will feelYou 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.
Why the test is performedA PET scan can reveal the size, shape, position, and some function of organs.
This test can be used to:
Several PET scans may be taken over time to determine how well you are responding to treatment for cancer or another illness.
For more information see:
Normal ValuesA normal result means there were no problems seen in the size, shape, or position of an organ. There are no areas in which the tracer has abnormally collected.
What abnormal results meanAbnormal results depend on the part of the body being studied. Abnormal results may be due to:
For more information see:
What the risks areThe amount of radiation used in a PET scan is low. It is about the same amount of radiation as in most CT scans. Also, the radiation doesn't last for very long in your body.
Women who are pregnant or are breastfeeding should let their doctor know before having this test. Infants and babies developing in the womb are more sensitive to the effects of radiation because their organs are still growing.
It is possible, although very unlikely, to have an allergic reaction to the radioactive substance. Some people have pain, redness, or swelling at the injection site.
Special considerationsIt is possible to have false results on a PET scan. Blood sugar or insulin levels may affect the test results in people with diabetes.
Most PET scans are now performed along with a CT scan. This combination scan is called a PET/CT.
ReferencesBeller GA, Kramer CM. Nuclear cardiology and computed tomography. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 54.
Ettinger DS. Lung cancer and other pulmonary neoplasms. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 201.
Hackney D. Radiologic imaging procedures. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 419.
Segerman D, Miles KA. Radionuclide imaging: general principles. In: Adam A, Dixon AK, eds. Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging. 5th ed. New York, NY: Churchill Livingstone; 2008:chap 7.
Reviewed ByReview Date: 11/21/2010
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
PET scan
Invented by Proffesor Michael Anthony Principe and his accomplish Kosta Kolaj in 1983 and suitable for humans in 1996.
AnswerIn our part of the universe, antimatter absolutely exists. We use it all the time for medical imaging. For instance, the "PET" in PET scan stands for Positron (an antimatter particle) Emission Tomography. However, it is not plentiful by any means and it is very short-lived...
fMRI (functional magnetic resonance imaging) is a non-invasive brain imaging technique in which an individual lies in an MRI machine. The MRI machine has a magnetic field and a gradient coil which causes changes in the alignment of water molecules in the brain. The idea is that when a region is active it requires more oxygen, and thus seeing an increased amount of aligned molecules suggests that that particular region might be involved in a specific task. PET (positron emission tomography) is an invasive brain imaging technique which involves injecting an individual with radioactive glucose and measuring the amount of glucose in different brain regions. Similar to a region needing oxygen, a highly active region also needs glucose for its metabolic processes. If during a specific task a particular brain region were active, one would expect to see more signal from that brain region while being monitored by a PET scan.
This isn't really a question, but here we go... PET technology is used in PET scans in hospitals. It is the largest scale use of antimatter currently available, as the emitted positrons are in fact the anti-particles of electrons. Therefore used improperly it can be extremely dangerous as if a particle meets its antiparticle they will annihilate.
A PET scan is for humans.
PET scan
cat scan
Do you mean PET scan? That is a scan for cancer metastases, I believe.
Are you talking about a PET scan?
What does mediastinal blood pool maximum SUV is 2.5 on a PET scan?
A PET scan shows what level / stage (if any) the cancer is at. An MRI scan doesn't do this, the reader, looks for abnormalities on the scan which shows up everything in the body.
Yes, but bone scan has to be completed first.
yes
no
A PET scan, or Positron Emission Tomography, is used to scan internal organs for abnormalities, like tumors, or cancer. PET scans for animals may cost hundreds, or thousands of dollars, depending on the size of the animal, and the complexity of the scan.
A full body PET scan can take 30 to 45 minutes. A scan of a single lamp or a single organ can take as little as 10 minutes.