Define "radiopharmaceutical."

A radiopharmaceutical is a radioactive compound utilized in the field of nuclear medicine, specifically designed for both imaging and treatment purposes. These compounds emit radiation and can be introduced into the body to target specific organs, tissues, or cellular receptors. When used for imaging, the emitted radiation is detected by specialized imaging devices, allowing healthcare professionals to visualize internal structures and functions within the body. This technique is valuable for diagnosing conditions such as cancer, heart disease, and bone disorders.

In therapeutic applications, radiopharmaceuticals can deliver targeted radiation to treat various medical conditions, including certain types of cancer. The ability to utilize radioactive materials in a controlled manner enhances the diagnostic and therapeutic capabilities in modern medicine. This precise targeting helps maximize treatment efficacy while minimizing damage to surrounding healthy tissues.

The other options refer to different categories of substances used in radiological practices but do not accurately define what a radiopharmaceutical is. Imaging agents for X-rays or contrast media for CT scans are not inherently radioactive, and non-radioactive substances serve entirely different functions in medical imaging and do not involve the unique properties and applications of radiopharmaceuticals.