Describing a structure that obstructs the passage of x-rays.

Describing a structure that obstructs the passage of x-rays.

• A. Radiopaque
• B. Radiolucent
• C. Radiography
• D. Radiometer

Answer: (A)

On an X-ray image, how a structure appears depends on how much X-ray is absorbed. Structures that block X-rays strongly—being dense or containing high atomic numbers—prevent many photons from reaching the detector, so they show up white or opaque. This property is described as radiopaque, making it the best description for a structure that obstructs the passage of X-rays. The opposite, radiolucent, refers to materials that X-rays pass through more easily and thus appear darker on the image. Radiography is simply the imaging method used to capture the image, and a radiometer is an instrument that measures radiant energy, not how X-rays interact with matter. For example, bone and metal are radiopaque, while air-filled spaces are radiolucent.

On an X-ray image, how a structure appears depends on how much X-ray is absorbed. Structures that block X-rays strongly—being dense or containing high atomic numbers—prevent many photons from reaching the detector, so they show up white or opaque. This property is described as radiopaque, making it the best description for a structure that obstructs the passage of X-rays. The opposite, radiolucent, refers to materials that X-rays pass through more easily and thus appear darker on the image. Radiography is simply the imaging method used to capture the image, and a radiometer is an instrument that measures radiant energy, not how X-rays interact with matter. For example, bone and metal are radiopaque, while air-filled spaces are radiolucent.