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.
Out of the listed options, the most accurate answer is: B. Screen mottle
Here's why the other options are not fully accurate:
A. Number of light photons/absorbed x-ray:
While rare earth screens generally convert a higher percentage of absorbed X-rays into light photons compared to calcium tungstate screens, the difference may not be significant in practical terms.
C. Speed:
Rare earth screens are actually faster than calcium tungstate screens, meaning they require less X-ray exposure to produce the same image density. This translates to a decrease in patient dose.
D. Patient dose:
As mentioned above, rare earth screens generally require less X-ray exposure for the same image quality, leading to a decrease in patient dose compared to calcium tungstate screens.
E. All the above:
Only a decrease in screen mottle is universally true for rare earth screens compared to calcium tungstate screens. While they offer faster speed and potentially lower patient dose, the difference in light photon conversion might not be noticeable in all settings.
Therefore, the primary advantage of rare earth screens over calcium tungstate screens lies in their ability to significantly reduce screen mottle. This mottle is a grainy pattern arising from variations in the screen's phosphor crystals, which can obscure image details. By minimizing this mottle, rare earth screens offer sharper and higher-quality radiographs, allowing for improved diagnostic accuracy.
Remember, the choice of screen material depends on various factors like desired image quality, patient dose considerations, and cost-effectiveness. Consulting with a qualified radiologist or radiographer would be helpful in determining the most suitable screen for your specific needs.
