Positron Emission Tomography: Definition, 4 Facts, Function, and How It Works

By | July 12, 2020
Positron Emission Tomography - PET

Positron Emission Tomography definition

Positron emission tomography or better known as the PET Scan is an imaging test used to evaluate the functioning of organs and body tissues. This type of imaging utilizes a nuclear or radioactive compound called the radiotracer, to transmit a reverse current of images to a computer.

Doctors utilize the results of a PET scan to measure some physiological functions. Among them are the use of oxygen, sugar metabolism, blood flow, even inflammatory reactions.

This examination uses Radiotracer to emit gamma rays, special cameras, and a computer for recording and analyzing data. The goal is to identify all sorts of changes or irregularities in cells that are indicative of disease progression or abnormalities.

This early detection is very important for the success of treatment procedures and treatments of various types of diseases.

In some cases, the results of a PET scan are combined with the results of a CT scan to create a more accurate diagnosis and detailed information that is not produced by other imaging tests. The specific location of anatomical anomaly is easier to be detected by combining imaging tests.

Positron Emission Tomography Facts

Here are some important points about PET scanning. More details are in the main article.

  • PET scans are often used to diagnose a condition or track their progress.
  • Used in conjunction with a CT or MRI, it can show how the body parts work.
  • PET scans are often used to investigate epilepsy, Alzheimer’s disease, cancer, and heart disease
  • Scans are painless, but patients should not consume any food for at least 4 to 6 hours prior to the scan. They must drink plenty of water.

Positron Emission Tomography Function

Positron emission tomography is an effective way of examining chemical activity within the body, which helps to detect abnormalities in the area. Generally, positron emission tomography is used for people with cancer, heart disease, or brain disorders.

Examining cancer

In cancer, cancer cells will absorb more radioactive material because the cells have a higher metabolism. As a result, cancer cells will look brighter than healthy cells. Positron emission tomography in cancer is used to see the spread of cancer, a response to treatment, and whether the cancer has been a relapse.

Examining heart organ

Positron emission tomography is used in the heart organ to detect the heart area that has decreased blood flow. By knowing the area, it can prevent further damage and determine whether the surgery can provide benefits.

Examining brain organ

In the brain organs, positron emission tomography detects areas that have the highest activity in a variety of situations, such as when speaking, counting, and so on. Positron emission tomography can also detect abnormalities, such as tumors, memory impairment, and seizures.

Why do you need a Positron Emission Tomography (PET) Scan?

PET scans are mainly used to detect and monitor conditions, including cancers, neurological (brain) disorders, and cardiovascular (heart-related) diseases. It can detect cancer before the cancer can be detected using other imaging techniques (eg. CT and MRI scans).

In addition, the tool also allows your doctor to determine, whether, and where to spread the cancer to other parts of the body.

A PET Scan can help with surgical planning for epileptic seizures by showing which part of the brain is causing the epilepsy. It is also used to examine Alzheimer’s disease and Parkinson’s diseases, as the resulting images can show more definite areas of the brain that are not functioning normally. 

Early detection of these neurological disorders will lead to more effective treatment.

How Positron Emission Tomography Works

In PET scanning, the engine detects radiation emitted by the radiotracer.

Radiotracer is made up of radioactive materials characterized by natural chemicals, such as glucose.

The radiotracer is injected into the body, where it moves into the cells that use glucose for energy.

The more energy a bunch of cells need, the more the Radiotracer will form at that location. This will appear on the image reconstructed by the computer.

Cells, or activities, will appear as “hot spots” or “cold spots.”

Bright active Area on PET scanning. They are known as “hot spots.”

Where the cell needs less energy, the area will become brighter. This is a “cold point.”

Compared to normal cells, cancer cells are very active in using glucose, so the radiotracer made with glucose will illuminate the area of cancer.

A radiologist will examine the resulting image on the computer, and report his findings to the doctor.

Examples of glucose-based radiotracer are Fluorodeoxyglucose (FDG). In the FDG, radioactive fluoride molecules are characterized by glucose to make the radiotracer. FDG is the most commonly used radiotracer today.

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