What best describes the dynamic range of a digital radiography detector?

• A. The detector's spatial resolution
• B. The grayscale bit-depth
• C. The span of exposures the detector can accurately convert to digital values
• D. The frame rate of image acquisition

Answer: (C)

Dynamic range describes how much exposure a digital radiography detector can handle and still produce a usable digital signal. It spans from the smallest signal that can be distinguished from noise up to the largest signal at which the detector begins to saturate. A wide dynamic range means the detector can accurately convert both very low and very high exposures, preserving detail across a range of tissues and patient sizes without losing information in shadows or highlights. This concept is about the detector’s exposure-to-digital value conversion across different scene brightness, not about how finely image details are sampled (spatial resolution), how many gray levels a image can show for contrast once recorded (grayscale bit-depth), or how fast images can be acquired (frame rate).