In which procedure do patients often receive a tracer injection?

A PET scan, or Positron Emission Tomography scan, is a specialized imaging procedure where patients receive a tracer injection. This tracer, which is typically a radioactive substance that emits positrons, helps to visualize metabolic processes in the body. During the PET scan, the tracer highlights areas of high biochemical activity, which can indicate the presence of cancer, brain disorders, or heart conditions.

The use of a tracer is crucial for PET scans, as it allows for a functional imaging approach, contrasting with other imaging methods that primarily provide structural information. While X-rays, CT scans, and ultrasounds are also valuable diagnostic tools, they do not use tracers in the same manner. Instead, they utilize different techniques; for example, X-rays employ ionizing radiation to create images of dense structures, CT scans take multiple images from various angles to construct cross-sectional views, and ultrasounds use sound waves to visualize soft tissues.