Understanding PET Scans: What 'Active' Means & What to Expect

A PET scan, or positron emission tomography scan, is a medical imaging technique that uses a biologically active tracer to produce a three-dimensional picture of one of your body's processes.

PET Scan

• In a PET scan, you are either injected with, inhale or ingest a mildly radioactive tracer. By using scanning devices doctors can trace the process of this tracer through your body allowing them to detect abnormalities.

Biologically Active

• Most PET scan tracers are biologically active. This means that they do not just pass through your body, but are taken up into particular organs or tissues. An active PET scan is one that uses one of these tracers.

Uses

• PET scans are used to detect and monitor the spread of cancer, measure blood flow to muscles, and map brain function.

Benefits

• PET scans provide information that cannot otherwise be discovered except through exploratory surgery, which is more expensive and more risky.

Risks

• While PET scans do involve introducing radioactive materials into your body, the amounts are so small that the radioactive exposure is minimal. The greatest discomfort is that the procedure may take several hours to complete.