Afraid of a PET scan? Let's get straight to the point!

Has your doctor told you to have a PET scan? Or have you heard this name somewhere? After hearing this, you may have felt a little scared and curious. 'PET' is the name given to an animal, and you may have wondered what kind of scan this is. Don't be afraid of anything. Today, we will talk about what this PET scan is, how it is done, and what it is used for in a very simple way, in language that you can understand.

Simply put, what is a PET scan?

The full name of the PET scan is Positron Emission Tomography scan . But none of us use that long name, it's called PET scan for short.

This is also a special test used to look inside our bodies. But it's a little different from other types of scans. It gives us a picture of how our organs and tissues are working .

For this test, a small amount of a very safe, radioactive chemical is injected into your body through a vein. We call this a radiotracer . Then, a PET scan is used to watch how this chemical moves throughout your body.

Think of it this way. The diseased cells in our bodies, especially cancer cells, are much "hungrier" than healthy cells. Their metabolism is very fast. So this radiotracer that we give (often it's attached to a sugar), those "hungry" diseased cells absorb it faster and more than healthy cells. It's like little kids eating chocolate.

Then, when you look at it with the scanner, the areas where the radiotracer has accumulated a lot, look like "lights have turned on." Doctors also call these "hot spots." By looking at those glowing areas, you can identify exactly where there is a problem in the body.

What is the difference between PET scan, CT and MRI?

Many people get confused about these three types of scans. All three of them take pictures of the inside of the body. But the way those pictures are taken and the information we get from those pictures are completely different. Let's try to understand this easily.

Often, doctors will order a PET-CT scan to get the benefits of both types of scans. This means that the PET scan and the CT scan are done at the same time, on the same machine. Then we can see both the structure (from the CT) and the function (from the PET) of the body in a single image. This helps a lot in making a very accurate diagnosis.

What kind of diseases does a PET scan look for?

A PET scan can measure important processes in our body, such as blood flow, oxygen consumption, and glucose metabolism. Therefore, it is used to diagnose various medical conditions.

1. For cancer:

PET scans are mostly used for cancer.

• To detect cancer: If there is a suspicion of cancer cells growing somewhere in the body, a PET scan is very useful to confirm it. For example, breast cancer, lung cancer, thyroid cancer, etc.
• See if the cancer has spread: Once a cancer is diagnosed, a single scan of the entire body can be used to check if it has spread (metastasized) to other parts of the body.
• See if you are responding to treatment: During cancer treatment (e.g. chemotherapy), PET scans are done to see if the treatments are killing cancer cells and shrinking the tumor.
• Check if the cancer has come back: This is also used to confirm if there is any suspicion that the cancer has come back after treatment is complete.
• Get an idea of ​​the prognosis: Doctors can also predict what the disease will be like by looking at the activity of the cancer.

2. For Heart Problems:

• After a heart attack, see how much damage has been done to the heart muscle.
• Determine whether blood flow to certain parts of the heart is reduced and whether those parts would benefit from angioplasty or coronary artery bypass surgery .

3. For Brain Disorders:

• See the function of brain tumors.
• To find the exact location in the brain where a seizure begins in someone with epilepsy .
• Identify changes in brain function in diseases such as dementia and Alzheimer's disease .

How should I prepare for a PET scan?

A PET scan is an outpatient procedure. That means you can go home the same day. Your doctor will give you the exact instructions you need. But in general, you should be careful about these things.

What happens during the scan?

When you go on the day of the scan, you will have this kind of experience.

1. Injection: First, a nurse will inject the radiotracer we talked about (usually a type called fluorodeoxyglucose (FDG) ) into a vein in your arm. You won't feel any difference when it's injected.

2. About an hour of rest: After that, you will be asked to sit in a chair in a quiet room for about an hour. This time is needed for the injected medicine to travel throughout the body and be absorbed into the necessary organs and tissues. It is very important to stay calm during this time, not moving or talking too much. Because if you move too much, the radiotracer can be absorbed into the muscles more, which can affect the results of the scan.

3. To the scanner: After an hour, you will be taken to the scanning room. You will be asked to lie down on an examination table connected to the scanner.

4. Scanning: The bed slowly moves into the scanner. The machine looks like a big donut. You are asked to remain still and motionless inside. Moving can blur the images. You may hear clicking and buzzing sounds from the machine while the scan is being performed. The entire process takes about 30 minutes.

5. After the scan: After the scan is complete, you will need to wait a while while the technician checks to see if the images are clear. If everything is OK, you can go home.

The entire test, including the injection, rest, and scanning, takes about two hours .

Are there any risks or side effects to this?

Many people are scared when they hear the word 'radioactive', but a PET scan is actually a very safe test.

However, there are a few rare cases where a risk may arise:

• Pregnant and breastfeeding mothers: PET scans are not performed in these cases because radiation can be harmful to the fetus and can be passed to the baby through breast milk.
• Allergies: Some people may have an allergy to the radiotracer or contrast dye used in a PET-CT scan. This is very rare. If this happens, the medical team is ready to treat you immediately.
• Diabetes: People with diabetes may have changes in the way the body absorbs the sugar-containing radiotracer. This can affect the results. Therefore, if you have diabetes, your doctor will advise you on how to change your diet and medications before the test.

The results of the scan are usually available within 24 hours . A radiologist, who has been specially trained to read PET scan images, will review the images, create a report, and send it to your doctor. The doctor will then explain the report to you.

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