PET Scans
Positron emission tomography (PET) scans are measure blood flow, oxygen use, and glucose metabolism to determine organ and tissue functioning. They can detect or monitor certain kinds of cancer, brain disorders, and heart disease. Physicians often use PET scans with CT scans to create images revealing abnormal metabolic activity.
PET scans often include a radioactive substance that is injected, inhaled, or swallowed. After the substance takes effect (up to an hour later), the patient lies on a table that slides into the scanner, like a closed MRI.