Which neuroimaging technique uses X-ray equipment to scan the brain at different angles and produce structure-only scans (CAT)?

• A. Computerised Tomography (CT)
• B. Magnetic Resonance Imaging (MRI)
• C. Positron Emission Tomography (PET)
• D. Electroencephalography (EEG)

Answer: (A)

This item tests understanding of how imaging techniques differ in what they reveal and how they work. CT uses X-ray beams that rotate around the head; the detectors measure how much X-ray signal is absorbed at different angles, and a computer reconstructs cross‑sectional images of the brain’s anatomy. These images show structure clearly but do not show brain activity or metabolism, so they’re described as structure-only scans. In contrast, MRI uses magnetic fields and radio waves to image soft tissues, PET uses a radioactive tracer to map metabolic activity, and EEG records electrical activity from the scalp.