What thickness of crystals yields better resolution, but cannot image higher keV photons?

• A. Thinner
• B. Thicker
• C. Same as standard
• D. Thinnest

Answer: (A)

Reducing crystal thickness improves spatial resolution because photons interact closer to the readout plane, reducing depth-related blur and parallax. That sharper localization comes at the cost of stopping power: thinner crystals absorb fewer photons, especially at higher energies. So a thinner crystal will give better resolution but is less able to image high-keV photons because it doesn’t absorb them efficiently. Among the options, a thinner thickness provides the best balance for improving resolution while limiting the ability to image higher keV photons, which is why it’s the best choice.