In scintigraphy, which statement is true?

• A. A CT scan is performed to produce cross-sectional images.
• B. A ultrasound-based method to visualize soft tissues.
• C. A non-imaging blood test.
• D. A radioactive pharmaceutical is injected into patient which concentrates to a specific organ and then radioactivity is detected by a gamma camera.

Answer: (D)

Scintigraphy relies on giving the patient a radioactive tracer that behaves like the body's own substances and concentrates in a specific organ. The gamma camera then detects the emitted gamma rays to create images that reflect function and tracer distribution, not just anatomy. This is why the statement about injecting a radiopharmaceutical that concentrates in a target organ and having its radioactivity detected by a gamma camera is true. The other options describe different imaging approaches: CT uses X-rays to produce cross-sectional anatomy, ultrasound uses sound waves to visualize tissues, and a non-imaging blood test doesn’t create images at all.