Both positron-emission tomography (PET) and computed tomography (CT) scans use energy to create images of the body and can diagnose many types of medical conditions. They differ in the type of energy they use and the reasons for use. Often, a PET scan is performed along with a CT scan to provide detailed images of the body.
Read more here: https://www.verywellhealth.com/pet-scan-vs-ct-scan-7095580
