Self-normalizing method to measure the detective quantum efficiency of a wide range of x-ray detectors

The detective quantum efficiency (DQE) is widely accepted as the most relev ant parameter to characterize the image quality of medical x-ray systems. I n this article we describe a solid. method to measure the DQE. The strength of the method lies in the fact that it is self-normalizing so measurements at very low spatial frequencies are not needed. Furthermore, it works on a ny system with a response function which is linear in the small-signal appr oximation. We decompose the DQE into several easily accessible quantities a nd discuss in detail how they can be measured. At the end we lead the inter ested reader through an example. Noise equivalent quanta and normalized con trast values are tabulated for standard radiation qualities. (C) 1999 Ameri can Association of Physicists in Medicine. [S0094-2405(99)00907-4].