Radiology Practice Test

Which of the following best describes a PET scan?

1. A procedure that uses sound waves to create images

2. A technique that detects metabolic activity in tissues

3. A method for examining bone density

4. A tool for measuring heart function

The correct answer is: A technique that detects metabolic activity in tissues

A PET scan, or Positron Emission Tomography scan, is specifically designed to assess metabolic activity within tissues. This imaging technique utilizes a radioactive tracer that is injected into the body. This tracer emits positrons, which are detected by the PET scanner. The distribution and concentration of the tracer indicate how active different tissues are metabolically. This is particularly valuable for identifying cancerous cells, as malignant tumors typically exhibit higher metabolic rates compared to normal tissues. The other options refer to different imaging modalities: sound waves are utilized in ultrasound procedures, bone density testing is typically accomplished through techniques like dual-energy X-ray absorptiometry (DXA), and heart function is evaluated through methods like echocardiography or nuclear imaging. Each of these methods serves unique purposes, highlighting the specificity and utility of PET scans in examining metabolic functions.