What is the primary function of a CT scan?

• A. It uses magnetic fields to create images of the body.
• B. It uses computer-processed combinations of X-ray measurements from different angles to produce cross-sectional images.
• C. It uses sound waves to create real-time images.
• D. It measures the electrical activity of the heart.

Answer: (B)

CT imaging relies on rotating X-ray beams and detectors around the patient, with a computer reconstructing the data into cross-sectional slices. The primary function is to create these cross-sectional images by combining X-ray measurements taken from multiple angles. This allows detailed visualization of internal structures in a plane and in 3D when multiple slices are stacked. This differs from MRI, which uses magnetic fields and radio waves; ultrasound, which uses sound waves for real-time imaging; and ECG, which measures the heart’s electrical activity. CT is fast and excels at showing bones, lungs, and vessels with contrast.