Which change will increase the contrast resolution of a digital radiographic system?

• A. Increased receptor size
• B. Increased bit depth
• C. Increased exposure latitude
• D. Decreased detector element (DEL) size

Answer: (B)

Contrast differences in digital radiography hinge on how many gray levels the system can display for each pixel. Increasing bit depth expands the number of possible gray values, so the image can represent subtler differences in tissue density. With more gray levels, small variations that once looked the same become distinct shades, boosting contrast resolution.

Changing receptor size mainly affects spatial resolution and field of view rather than the number of gray levels, so it doesn’t raise the system’s ability to distinguish close gray tones. Exposure latitude relates to how much exposure can vary while still producing an acceptable image; it helps with consistency but doesn’t inherently increase the range of detectable gray shades. Decreasing detector element size improves sampling and spatial detail but can raise image noise, which can actually reduce perceived contrast resolution rather than enhance it.