What does computed tomography (CT) use to produce cross-sectional images of the body?

Computed tomography (CT) utilizes X-rays and advanced digital processing to create detailed cross-sectional images of the body. In a CT scan, X-ray beams are emitted from a rotating source and pass through the body, where they are attenuated by different tissues at varying degrees. These X-rays are then detected on the opposite side, and a computer processes the data to reconstruct images of the body's internal structures in slices, or cross-sections.

The use of digital processing is crucial as it enhances the quality of the images and provides a means for visualization in various planes or 3D renderings. The combination of the penetrative ability of X-rays and sophisticated image reconstruction techniques is what enables CT to provide detailed information about various anatomical structures, making it an essential tool in medical diagnostics.

Other modalities mentioned in the incorrect options, such as radioactive isotopes, ultrasound waves, or magnetic resonance, utilize fundamentally different mechanisms to create images and are not part of the CT imaging process.