In digital radiography, increasing pixel bit depth primarily increases the number of grayscale steps available in the image.

• A. It increases spatial resolution.
• B. It increases grayscale levels and dynamic range.
• C. It increases field of view.
• D. It increases exposure latitude.

Answer: (B)

Pixel bit depth controls how many grayscale steps a digital image can display. When you increase bit depth, each pixel can take more distinct gray values, which means more grayscale levels and a finer tonal range. This improves contrast resolution, allowing subtle differences between tissues to be seen more clearly and reducing banding in smooth regions.

This does not change spatial resolution, which depends on how large the pixels are and how densely they sample the scene, nor does it alter the field of view, which is set by detector size. While a higher bit depth can provide a broader effective dynamic range and help accommodate varying exposures, the primary impact is the increase in grayscale levels that the image can represent.