Which imaging technique uses a gamma camera to detect emitted radiation for functional imaging?

• A. MRI
• B. CT
• C. Scintigraphy
• D. Ultrasound

Answer: (C)

Functional imaging shows how tissues work by tracking a tracer’s distribution and activity inside the body. Scintigraphy uses a radiopharmaceutical that targets specific organs or processes. As the tracer decays, it emits gamma photons, which are detected by a gamma camera. The camera translates these emissions into images that reflect where the tracer concentrates, revealing physiological activity such as blood flow, metabolism, or organ function. This contrasts with MRI and CT, which map anatomy using magnetic fields or X-ray attenuation, and ultrasound, which uses sound waves. The gamma-camera approach is specifically designed for functional information, making scintigraphy the best fit for this purpose.