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.
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
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