Which description best defines a CT scan?

• A. A nuclear medicine imaging device that produces a 3-D image.
• B. A device that creates an image based on sound waves.
• C. An X-ray, using specialized equipment, that takes cross-sectional pictures of the body.
• D. Magnetic imaging equipment that uses a radio frequency pulse to create an image.

Answer: (C)

CT scanning is a computed tomography procedure that uses X-ray beams rotating around the body and detectors to measure how tissues attenuate the X-rays. A computer then reconstructs these measurements into cross-sectional images, or slices, of the body. By stacking these slices, a three-dimensional view of the area can be created. This description matches an X-ray based exam with specialized equipment that produces cross-sectional pictures.

That’s distinct from other imaging types: nuclear medicine images rely on radioactive tracers to show function, ultrasound uses sound waves to create real-time images, and MRI uses strong magnetic fields with radiofrequency pulses to generate images.