DANB Radiation Health and Safety (RHS) Practice Exam

What does the term radiopaque mean?

1. Substances that allow Xrays to pass through easily

2. Substances that block Xrays

3. Low density materials

4. Substances that emit radiation

The correct answer is: Substances that block Xrays

The term radiopaque refers to substances that block X-rays. When an object is considered radiopaque, it means that it has a high atomic number or density, preventing X-rays from passing through it. This blocking action contrasts with radiolucent materials, which allow X-rays to pass through with little resistance. Radiopaque materials appear white or light on an X-ray image, providing essential contrast that helps in diagnosing and identifying structures within the body. For instance, materials like bone and certain types of contrast agents used in medical imaging are radiopaque; they absorb the X-rays and thus appear distinctly on the X-ray film, allowing for better visualization of anatomical structures. Understanding the property of radiopacity is critical in radiation health and safety, as it informs practitioners on how to use imaging techniques effectively while ensuring patient safety and minimizing exposure to radiation.