In radiology, what does the term "radiopaque" refer to?

The term "radiopaque" refers to substances that do not allow X-rays to pass through them. In radiology, this property is significant because radiopaque materials appear white or light on X-ray images. These substances absorb the X-rays, preventing them from reaching the film or detector on the other side, which is fundamental for creating contrast in diagnostic imaging.

Radiopaque materials include dense structures like bones and certain contrast agents used in imaging studies. Understanding the concept of radiopacity is crucial for interpreting radiographic images, as radiologists rely on the contrast between radiopaque and radiolucent (X-ray transparent) materials to identify anatomical structures and possible abnormalities.