Computed tomography (CT) scan is best described as which of the following?

• A. Ultrasound imaging of tissues
• B. Positron emission tomography
• C. Magnetic resonance imaging
• D. Computed tomography scan

Answer: (D)

The main idea is that computed tomography is an imaging method that uses rotating X-ray beams and computer reconstruction to create cross‑sectional pictures of the body. Saying it is a computed tomography scan is correct because the term “scan” simply refers to the data-collection process of that same technique, resulting in the CT images. The other options describe different imaging methods: ultrasound uses sound waves to image tissues, PET uses a radioactive tracer to visualize metabolic activity, and MRI uses strong magnetic fields and radiofrequency pulses to image soft tissues. So the description that matches the actual technique by name is the CT scan.