In digital radiography, increasing bit depth primarily improves which aspect?

• A. Contrast resolution
• B. Spatial resolution
• C. Dynamic range
• D. Exposure latitude

Answer: (A)

Increasing bit depth gives each pixel more possible gray values, expanding grayscale detail in the image. That means you can distinguish subtler differences in tissue density, which directly improves contrast resolution—the ability to discriminate between slight variations in brightness. Spatial resolution, on the other hand, is about how sharp structures appear and depends more on pixel size and imaging geometry than on how many gray tones are available. Dynamic range and exposure latitude relate to the overall range of signal intensities the system can capture or display; increasing bit depth enhances grayscale granularity, not the physical range of exposures the detector can handle.