What is contrast resolution?

• A. Ability to distinguish different densities (bit)
• B. Number of gray values
• C. Number of pixels per inch
• D. Scanner speed

Answer: (A)

Contrast resolution is about how well an imaging system can separate small differences in density or shade in an image. This ability depends on the number of gray values the system can display, which is set by the bit depth per pixel. More bits mean more gray levels, so subtle differences between tissues become visible. That makes the description of distinguishing different densities the best way to capture the concept. In contrast, spatial resolution (how many pixels per inch) affects where details appear, not how subtle the shades are, and scanner speed relates to how quickly data are acquired rather than gray-scale discrimination.