![PET Scan](https://images.medicinenet.com/images/article/main_image/what-is-a-breast-positron-emission-tomography-used-for.jpg?output-quality=75)
Positron emission tomography (PET) scans are used to identify early indications of heart disease, cancer, metastasis, and brain disorders. The abnormal cells are traced using an injectable radioactive tracer.
A PET-CT combo scan generates three-dimensional pictures for a more precise diagnosis and differentiates normal and abnormal cells in the body.
What is a PET scan?
A positron emission tomography (PET) scan is a type of nuclear medicine imaging test. Looking at blood flow, metabolism, and oxygen utilization, various bodily tissues are investigated to detect specific problems. The effectiveness of any treatment can be evaluated using PET scans.
The results of this test inform the medical professional about the structure and operation of the organ or tissue. It provides details on its biological characteristics.
A PET-CT scan is a common procedure that combines a PET scan with a CT scan to provide more precise information on changes in metabolism and locations of the pathological changes inside the body.
How does it work?
A tiny quantity of a radioactive chemical called a radioactive tracer is utilized for a positron emission tomography (PET) scan. Cancer cells that have a hyperactive metabolism will take up the tracer more intensively. This tracer can then be detected on a connecting computer with help of a gamma camera.
- The radioactive tracers are attached to a chemical compound that is utilized by a specific organ or tissue during metabolism. These substances can be oxygen, carbon, or glucose.
- For instance, because glucose is commonly utilized for metabolism, radioactive material is added to it to form radionuclide fluorodeoxyglucose (FDG), which is used in PET scans of the brain. PET scanning frequently uses FDG.
- Depending on the scan's objective, other chemical molecules might be employed. A radioactive form of oxygen, carbon, nitrogen, or gallium could be used as the radionuclide if the blood flow and perfusion of a particular organ or tissue are of interest.
- An intravenous line is used to inject the radioactive tracer or sugar into the vein. It circulates in the blood and gathers in places where cells are active. The body is slowly scanned by the PET scanner during this period.
- The body is then mapped out by a computer. The tissue appears brighter or darker depending on how much radioactivity has accumulated in it. The amount of sugar absorbed or the level of cell activity in that organ or tissue is detected.
- Cancer cells, for instance, use a lot of sugar and would appear as bright areas or “hot spots” on a PET scan. Heart tissue that has been damaged will be less active and require less sugar. If contrasted with the healthy cardiac tissue, it would appear as a darker area.
![](https://images.medicinenet.com//images/slideshow/essential-screening-tests-for-women-s1-doctor-examining-woman-patient.jpg)
SLIDESHOW
Health Screening Tests Every Woman Needs See SlideshowWhat does a PET scan check for?
Positron emission tomography (PET) scans are typically employed to examine organs or tissues for the presence of illness or other disorders.
PET scans are used for the following:
- To identify neurological disorders, such as Alzheimer's disease and other forms of dementia
- 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)
- Epilepsy (a brain disorder involving recurrent seizures)
- Stroke (a vascular insult to the brain tissue)
- To identify the precise cancerous spot that will be operated on during brain surgery
- To identify the body's other regions where cancer has migrated from the original cancer spot
- To assess the effectiveness of cancer treatment
- To assess the heart's blood flow, whether treatment is necessary to increase heart blood flow, and the effects of a heart attack
- To distinguish lung lesions or tumors that were identified on a chest CT scan or X-ray
- To search for malignancies that have returned following treatment and discover them earlier
- To map out how the human heart and brain normally function
What are the risks of a PET scan?
The radioactive tracer contains a very small amount of radiation. It does not linger in the body for very long but you could be radioactive for a certain time. During this time, you should stay away from kids and pregnant women and make sure you urinate and move your bowels using a separate washroom.
After a positron emission tomography (PET) scan, you should drink lots of water to get rid of radioactive medication.
In general, PET scans are risk-free and rarely result in complications unless there is an allergy to the tracers. The following are the exceptions:
- PET scans should not be done on women who are carrying a child or nursing a baby. Radiation can transfer from breast milk to an infant and can harm an unborn child.
- Some people react allergically to the radioactive tracers used in PET scans or the contrast dyes used in CT scans. Your healthcare team may prescribe medicine to you to swiftly slow down and stop this response.
- The radiotracer's sugar may not be absorbed by those with diabetes, which could alter scan results. Before the test, your doctor may recommend adjusting your diet and medicines.
PET Scan. https://www.oncolink.org/cancer-treatment/procedures-diagnostic-tests/nuclear-medicine-tests/pet-scan
About Your PET-CT with FDG Tracer. https://www.mskcc.org/cancer-care/patient-education/pet-ct-fdg
PET Scan. https://www.medanta.org/medical-imaging-radiology/technology/pet-scan/
Positron emission tomography scan. https://www.mayoclinic.org/tests-procedures/pet-scan/about/pac-20385078
PET Scan. https://my.clevelandclinic.org/health/diagnostics/10123-pet-scan
PET Scan (Positron Emission Tomography). https://www.webmd.com/a-to-z-guides/pet-scan
Positron Emission Tomography (PET). https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/positron-emission-tomography-pet
Top What Does a PET Scan Check For Related Articles
Blood Basics Test Quiz
What do you know about blood? It runs all through your body, so educate yourself! Take this blood basics quiz to learn about human blood!Chest X-Ray
Chest X-Ray is a type of X-Ray commonly used to detect abnormalities in the lungs. A chest X-ray can also detect some abnormalities in the heart, aorta, and the bones of the thoracic area. A chest X-ray can be used to define abnormalities of the lungs such as excessive fluid (fluid overload or pulmonary edema), fluid around the lung (pleural effusion), pneumonia, bronchitis, asthma, cysts, and cancers.CT Scan vs. MRI
CT scan (computerized tomography) is a procedure that uses X-rays to scan and take images of cross-sections of parts of the body. CT scan can help diagnose broken bones, tumors or lesions in areas of the body, blood clots in the brain, legs, and lung, and lung infections or diseases like pneumonia or emphysema.
MRI (magnetic resonance imaging) is a procedure that uses strong magnetic fields and radiofrequency energy to make images of parts of the body, particularly, the organs and soft tissues like tendons and cartilage.
Both CT and MRI are painless, however, MRI can be more bothersome to some individuals who are claustrophobic, or suffer from anxiety or panic disorders due to the enclosed space and noise, the machine makes.
MRI costs more than CT, while CT is a quicker and more comfortable test for the patient.
What Is the Difference Between a Bone Scan and a CT Scan?
A bone scan and a computed tomography (CT) scan are both used to diagnose various bone conditions. The specific use of a bone scan is to diagnose active bone diseases, such as osteoporosis, Paget’s disease or the spread of cancer into the bone. A CT scan is a high-resolution X-ray that gives detailed information about organ anatomy.Family Health History: Genetics, DNA Testing and Your Health
WebMD explains why your doctor asks about your relatives' health conditions and how you can get the information if you don’t know.Family Health: The Truth About Mail-In DNA Tests
If you're thinking about using an at-home DNA test kit, here are a few things to think about before mailing it in.How Accurate Is a Myocardial Perfusion Scan?
A myocardial perfusion scan (radionuclide myocardial perfusion imaging [rMPI] or nuclear stress test) is an imaging technique to study how well the blood flows through the heart muscle. The sensitivity, specificity and accuracy of cardiac imaging with single-photon emission computed tomography (SPECT) is between 44 percent and 70 percent depending on the blood vessels involved.How Much Radiation Is in a Pediatric CT Scan?
While X-ray imaging exposes children to low doses of radiation, pediatric CT scans deliver about 200 times higher radiation exposure than other examinations.Is a Bone Scan the Same as an MRI?
A bone scan is a nuclear imaging technology, whereas magnetic resonance imaging (MRI) uses magnetic waves to create a three-dimensional (3D) image of an organ. Therefore, they are different.Men's Screening Tests
Getting the right screening test at the right time is one of the most important things a man can do for his health. Learn at what age men should be screened for prostate cancer, high blood pressure, cholesterol and other health risks.MRI (Magnetic Resonance Imaging Scan)
MRI (or magnetic resonance imaging) scan is a radiology technique which uses magnetism, radio waves, and a computer to produce images of body structures. MRI scanning is painless and does not involve X-ray radiation. Patients with heart pacemakers, metal implants, or metal chips or clips in or around the eyes cannot be scanned with MRI because of the effect of the magnet.What Can Be Diagnosed With an Abdominal CT Scan?
Learn four conditions that are diagnosed using an abdominal computed tomography (CT) scan.What Is the Difference Between A-Scan and B-Scan?
A-scan and B-scan are both types of ultrasound examinations performed for eye evaluation. A detailed eye examination tells not only about the structures of the eyes but also about any underlying health conditions such as high blood pressure and diabetes.When Do You Need a Target Scan While Pregnant?
A target scan is an important and required prenatal ultrasound screening during the second trimester of pregnancy and is normally done between 18 and 20 weeks of gestation.