What Happens During a PET Scan?
PET images are different from more conventional imaging tests, such as X-ray, CT, ultrasound, and MRI. These images show what the tissues look like. PET images contain information about how tissues are functioning. In cancer, cells begin to grow at a much faster rate, using more sugars like glucose than normal tissues. PET works by using a small amount of a radioactive tracer attached to glucose or other compounds. The scanner looks to see which areas are using more glucose—a sign of possible cancer. If you’re getting a PET scan, typically, you’ll be told not to eat or drink anything after midnight the night before your scan. You can have a PET scan as an outpatient. The day of your scan, you are injected with a small amount of radioactive glucose (or similar tracer). It travels through your body and eventually collects in the organs or tissues that are using the glucose. There is no danger to you from this injection. After the injection, you will wait approximately an hour while the t
