Which concept refers to the ability to differentiate small changes in density as displayed on an image?

• A. Contrast
• B. Contrast resolution
• C. Density
• D. Dynamic range

Answer: (B)

The ability to differentiate small changes in density as displayed on an image is contrast resolution. This is about how finely the image can show gray shades—how many distinct density levels the system can reliably distinguish. When contrast resolution is high, subtle differences in brightness corresponding to slight density changes become visible, which helps in identifying early or borderline findings. In dental radiography, this matters because subtle variations in bone or tooth density may indicate pathology; digital systems achieve this by having a wide gray-scale (bit depth) and proper display settings. Contrast, by itself, refers to the difference in appearance between two areas, not the system’s capacity to resolve many incremental density steps. Density describes how dark or light the image appears overall, and dynamic range refers to the span of densities the system can record overall.