PET stands for Positron Emission Tomography. It is a type of test that takes pictures of the inside of your body. It uses a small amount of a radioactive sugar to help find certain diseases early. It can also show how well your treatment is working.
CT stands for Computed Tomography. It uses x-rays to show pictures of your bones and other parts of your body.
The technologist adds the PET pictures and CT pictures together. This way, the radiologist can get a better picture of what is happening in your body. This will help them decide whether there is something wrong in your body.
Please note the "What to Expect" instructions for PET/CT provided are specific for oncology.