How does high Detective Quantum Efficiency (DQE) affect the required exposure to achieve a given image quality?

• A. High DQE Requires Higher X-Ray Exposure
• B. High DQE Allows Lower Exposure for Similar Image Quality
• C. DQE Is Independent of Exposure
• D. DQE Decreases with Increased Exposure

Answer: (B)

DQE is about how efficiently a detector turns incoming X-ray signal into a clear image with acceptable noise. When DQE is high, more of that signal is captured and converted into useful image information, so you can achieve the same image quality with less radiation dose. In practical terms, a high-DQE detector lets you lower the exposure and still reach the target detail and noise level, which is why the correct idea is that high DQE allows lower exposure for similar image quality. The other statements contradict this dose-saving advantage by implying you’d need more exposure, or that DQE is unconnected to exposure, which isn’t the case.