Higher speed screens are made of thicker phosphor layer and larger crystal size. Which option best describes this design?

Higher speed screens are made of thicker phosphor layer and larger crystal size. Which option best describes this design?

• A. Increase speed by thicker phosphor layer and larger crystals
• B. Decrease speed by thinner layer and smaller crystals
• C. No effect on speed
• D. Requires more X-ray exposure

Answer: (A)

Screen speed is how much light is produced for a given amount of X-ray exposure. Higher speed screens convert X-rays into light more efficiently, so you can achieve the same image brightness with less exposure. A thicker phosphor layer provides more material to absorb X-rays and emit light, while larger crystal size increases light output per interaction. Together, these changes boost the light signal and thus the screen’s speed. The trade-off is reduced spatial resolution, since larger crystals scatter more light and blur fine detail. Therefore, this design describes increasing speed. If the phosphor layer were thinner and the crystals smaller, there would be less light produced, lowering speed and requiring more X-ray exposure to reach the same image density.

Screen speed is how much light is produced for a given amount of X-ray exposure. Higher speed screens convert X-rays into light more efficiently, so you can achieve the same image brightness with less exposure. A thicker phosphor layer provides more material to absorb X-rays and emit light, while larger crystal size increases light output per interaction. Together, these changes boost the light signal and thus the screen’s speed. The trade-off is reduced spatial resolution, since larger crystals scatter more light and blur fine detail. Therefore, this design describes increasing speed. If the phosphor layer were thinner and the crystals smaller, there would be less light produced, lowering speed and requiring more X-ray exposure to reach the same image density.