A PET scan (Positron Emission Tomography) is a type of imaging test that helps doctors see how tissues and organs inside the body are functioning. Here’s how it works:

Tracer Injection: Before the scan, a small amount of radioactive material called a tracer is injected into the bloodstream. This tracer is usually a form of glucose (sugar), as cells in the body naturally use glucose for energy.

Absorption: The tracer travels through the blood and is absorbed by the organs and tissues that are being examined. Because cancer cells, for example, use glucose at a higher rate than normal cells, they absorb more of the tracer.

Scanning: The patient is then placed in a PET scanner, which is a large machine shaped like a doughnut. The scanner detects the radiation emitted by the tracer and creates detailed images showing where the tracer is concentrated in the body.

Image Analysis: Doctors analyze the images to identify areas of abnormal metabolic activity. For example, high levels of tracer in a particular area could indicate cancer, while low levels might indicate conditions like heart disease or brain disorders.