Which combination yields the highest spatial resolution?

• A. large DEL size, small DEL pitch, high fill factor
• B. large DEL size, large SEL pitch, high fill factor
• C. small DEL size, small DEL pitch, high fill factor
• D. small DEL size, large DEL pitch, small fill factor

Answer: (C)

Spatial resolution improves when the detector samples the image more finely and uses as much of each detector element for signal as possible. Smaller detector element size reduces the footprint of each sample, while a smaller pitch increases the sampling density across the image, capturing more detail. A high fill factor ensures most of the detector element area is active, so signal collection is efficient and not lost to dead space, preserving image sharpness.

Thus, the combination with the smallest element size, the smallest pitch, and a high fill factor provides the greatest sampling density and signal efficiency, yielding the highest spatial resolution. Larger element size or larger pitch introduces coarser sampling and greater dead space, which blurs fine details and lowers resolution.