Which imaging modality diagnoses disease by administering a radioactive material?

Which imaging modality diagnoses disease by administering a radioactive material?

• A. Computed Tomography
• B. Ultrasound
• C. Magnetic Resonance Imaging
• D. Nuclear Medicine

Answer: (D)

Putting a radiopharmaceutical into the patient to track physiological processes is what nuclear medicine does. After administration, the radioactive tracer distributes according to the body’s function, and the emitted radiation is detected by a gamma camera, SPECT, or PET scanner. The resulting images reveal how organs and tissues are working—for example, bone turnover, thyroid uptake, or myocardial blood flow—not just their shape. This functional information comes from the radiotracer itself, rather than from purely anatomical signals. In contrast, CT, ultrasound, and MRI rely on X-ray attenuation, sound waves, or magnetic fields, respectively, and do not depend on administering a radioactive material for the diagnostic signal. Hence, the modality that diagnoses disease by administering a radioactive material is nuclear medicine.

Putting a radiopharmaceutical into the patient to track physiological processes is what nuclear medicine does. After administration, the radioactive tracer distributes according to the body’s function, and the emitted radiation is detected by a gamma camera, SPECT, or PET scanner. The resulting images reveal how organs and tissues are working—for example, bone turnover, thyroid uptake, or myocardial blood flow—not just their shape. This functional information comes from the radiotracer itself, rather than from purely anatomical signals. In contrast, CT, ultrasound, and MRI rely on X-ray attenuation, sound waves, or magnetic fields, respectively, and do not depend on administering a radioactive material for the diagnostic signal. Hence, the modality that diagnoses disease by administering a radioactive material is nuclear medicine.