Detective quantum efficiency of an energy resolving photon counting detector

The output response characteristics of an X-ray photon counting detector are measured experimentally and simulated using a Monte Carlo method in order to quantify the loss of statistical information due to pile-up. The analysis is applied to idealize counting detector models, but is adaptable to realistic event processing that is not amenable to analytic solution. In particular, the detective quantum efficiency (DQE) is calculated as a function of flux rate and shown to have an intermediate zero for the paralyzable case at the maximum periodic rate. The progressive degradation of the spectral response as a function of increasing flux rate is also modeled. Analogous metrics to DQE are defined in regards to the detector's ability to resolve atomic number and enhance image contrast based on atomic number differentiation. Analytic solutions are provided for the output and linearized response statistics and these interpolate well across the Monte Carlo and experimental results.