X-Rays Made Easy

What is It?

    Positron emission tomography scans, otherwise known as PET scans, are used for checking diseases in the body by showing how different organs and tissues are working. Dyes with radioactive substances called tracers are used and injected into the body to produce these images. Most of the time, PET scans are used to detect cancers, heart problems, problems with the nervous system or brain disorders, which means the scans are often performed in the brain, heart, breast or lung.

​

How It Works

    PET scans are special and different from CT scans or MRIs because they are able to provide the best view of diseases such as brain tumors, memory disorders, seizures and coronary artery disease. When detecting cancer, PETs can even show how cancer metabolizes and whether or not it has spread to new areas. They can also show how tumors are responding to chemotherapy treatments, or how well you are responding to other illnesses. Furthermore, PET scans can reveal where there might be poor blood flow to the heart, and check normal brain function.

​

Process

    The test is performed by injecting a small amount of radioactive material, the tracer, into the body. They can either be injected through an IV (into the vein) on the patient’s elbow. Another method of injecting tracers is by inhaling a gas. After about an hour, the tracer is absorbed into organs and tissues. At this time, the patient lays down on a table and is slid into a large tunnel-like scanner. At this point, the PET detects signals coming from the tracer. A connected computer is able to change these PET signals into 3D color pictures that must be interpreted.

​

Risks

    Since PET scans involve radiation, they have the ability to affect the body and those who take these tests are put at risk. However, the amount of exposure to harmful radiation is minimal in this particular scan, and often time, the radiation levels won’t affect the normal body processes. It’s important to remember that in comparison to how useful these scans are in diagnosing possibly fatal diseases, the risks are not as important. Despite this, it’s important to still take precautions. Individuals who are pregnant or breast feeding are not recommended to get PET scans. This is because babies/infants who are still developing are extremely sensitive to radiation, and even a small amount can be detrimental. People who are claustrophobic, uncomfortable with needles, or may have allergic reactions to PET tracers are also recommended to speak to their doctors are search for alternate methods.

​

PET-CT Scans

    Advancements in technology have even allowed for a combination of PET scans and CT scans to create even greater detail. These tests are known as PET-CT scans. They take X-rays of body structures and use tracers at the same time, resulting in an image that shows the activity of cells and exactly where changes are occurring. PET-CT scans are generally used for cancer, and are available in many major cancer hospitals. However, these tests aren’t necessary for all cancer patients.