What Is a PET Scan?

If you or someone you care about requires a PET scan, it's normal to be nervous -- especially if you've never gone through the process before. You may be wondering what a PET scan entails, or even simply what it is. This incredible imaging technology is known as positron emission tomography (PET), and it lets physicians see how organs and tissues are functioning. It's used to rule out such issues as heart problems, cancer, epilepsy, and Alzheimer's disease. Here is some helpful information to help fully answer the question: "What is a PET scan?"

How PET Scans Work

Your health care provider will start the procedure by injecting you with a harmless dye. The PET scan machine detects rays this dye emits, and the information it gathers is then sent to a computer that rearranges the data to display vivid 3-D representations of an organ's size, shape, and function. Other diagnostic imaging technologies, such as MRIs and CTs, are sometimes employed simultaneously to provide a number of perspectives. The test lasts from 30 minutes to more than an hour, and the results are in your doctor's hands usually within two or three days.

How the Dye Creates Images

The injected dye is key to creating the image, and your provider will add different substances to enhance the view of any particular organ. As the dye breaks down, the PET scanning machine detects it and converts it into imagery. Using a variety of colors and shades, the resulting display reveals a dynamic and extremely accurate image that often provides the answers your doctor is looking for.

What to Expect

In some cases, you may not be able to eat for a few hours before the test, but generally there is nothing special you need to do to prepare for a PET scan. When you arrive for your appointment, you'll be asked if you are claustrophobic, pregnant, or allergic to dye, and whether you've had any surgeries in the past. Before you enter the machine, the technologist will insert an IV needle and inject the dye. As it runs through your body, you'll feel a slight warm sensation. Your health care provider will then make as comfortable as possible and may even offer you a mild sedative.

After this preparatory work, you'll enter the machine. Most people are able to relax, and some even fall asleep. Many facilities offer optional music through a headset, which you'll be wearing both for noise reduction and to hear your provider's instructions. After the test is complete, you usually have to stay in the machine for a few minutes while the technologist ensures that the images came through. If you were given a sedative, you'll likely need someone to give you a ride home.

So, what is a PET scan? It is one among an arsenal of imaging technologies that have helped save countless lives. If your health care provider has ordered this test for you, you'll now be armed with the right information to be prepared for this common procedure. If a close friend or relative has to go through it, assure them that it's a simple, safe process that's really pretty amazing and helps doctors make key decisions.