In radiography, which term describes the white areas where X-rays were blocked?

• A. Radiolucency
• B. Radiopacity
• C. Opacity
• D. Luminosity

Answer: (B)

The main idea is X-ray attenuation: denser structures block more X-ray photons, so they show up white on the image. This white appearance is described by radiopacity—the property of resisting X-ray penetration. Radiopaque areas correspond to tissues or materials like bone or metal that strongly attenuate the beam. In contrast, radiolucent areas are dark because X-rays pass through more easily. Opacity and luminosity aren’t the standard terms used to describe this specific radiographic contrast. So the white areas where X-rays were blocked are radiopaque, described by radiopacity.