PET Scan Test
A PET scan is a nuclear imaging test that shows how well your tissues and organs are working. It is often used to check for cancer, heart disease, and brain disorders.
What this test measures
A PET scan measures chemical activity in your body, including blood flow, oxygen use, and metabolism. It uses a safe radioactive tracer to highlight areas with high chemical activity, which can be a sign of disease.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
Bright spots on a PET scan may be a sign of cancer.
Frequently asked questions
What does a PET scan measure?
A PET scan measures chemical activity in your body, such as blood flow, oxygen use, and metabolism.
How is a PET scan done?
You get an injection of a small amount of a safe radioactive tracer, which settles in areas with high chemical activity.
What can a PET scan diagnose?
It can help diagnose or monitor certain cancers, heart disease, and brain disorders like Alzheimer's.
What does a bright spot on a PET scan mean?
Cancer cells show up as bright spots on a PET scan.
Is a PET scan always done alone?
No, a PET scan is often done along with a CT scan.
Related lab tests
Sources
- MedlinePlus: PET Scan — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.