Detective Quantum Efficiency (DQE) is a:

• A. Score that describes the ability to convert remnant x-ray beam into a high-quality image
• B. Graphical representation of recorded exposure values
• C. Mathematical equation used to correct brightness and contrast
• D. Component that converts an electrical signal into a digital signal

Answer: (D)

DQE is a measure of imaging performance that tells you how efficiently the system converts the incoming x-ray signal into a usable, high-quality image while accounting for noise and how this quality changes with different spatial details. It isn’t a physical part of the machine; it describes how well the detector and readout process preserve signal as the image is formed. Typically DQE is defined as a function of spatial frequency and compares the output signal-to-noise ratio to the input signal-to-noise, with higher values indicating better image quality for the same radiation dose. It’s a performance metric for the whole detection and processing chain, not a single component like an analog-to-digital converter.