when compared with calcium tungustate rare earth screens generally result in decrease of

when compared with calcium tungustate rare earth screens generally result in decrease of

• a. Number of light photons/absorbed x-ray
• b. Screen mottle
• c. Speed
• d. Patient dose
• e. All the above

The answer is e. All the above.

Here's why:

- Number of light photons/absorbed x-ray:

Rare-earth screens convert more X-ray energy into light photons compared to calcium tungstate screens, leading to a higher number of light photons per absorbed X-ray.

- Screen mottle:

Rare-earth screens generally exhibit more mottle than calcium tungstate screens due to the structure of the phosphor layer. This can appear as a grainy texture on the radiographic image.

- Speed:

Rare-earth screens are considered faster than calcium tungstate screens, meaning they require less x-ray exposure to produce an image of the same density. This translates to shorter exposure times and reduced radiation dose to the patient.

- Patient dose:

One of the primary advantages of using rare-earth screens is the significant reduction in patient radiation dose compared to calcium tungstate screens. This is due to their higher efficiency in converting X-ray energy into light photons, allowing for shorter exposure times without compromising image quality.

Therefore, when compared to calcium tungstate screens, rare-earth screens generally result in a decrease in all the listed factors: number of light photons/absorbed X-ray, screen mottle, speed, and patient dose.