User-friendly, ultra-fast simulation of detector DQE(f)

Development of the indirect scintillating detector is hindered not only by the cost and lead-time of manufacturing but also the computational resources required for numerical modeling. The simulation is bogged down by the number of x-ray photons (gammas) required to duplicate the experimental flood image ensemble necessary to characterize the noise power spectrum (NPS), a key input into the detective quantum efficiency (DQE). The simulation approach presented in this work exploits our previously reported procedure named Fujita-Lubberts-Swank (FLS)(6). This novel technique computes the Lubberts NPS from an ensemble of single gamma point spread functions (PSF) and, as a result, allows for a significant reduction in the number of simulated particles, enabling full DQE(f) simulations with optical transport in less than one CPU-hour. For a given detector and spectrum, the FLS execution time is determined primarily by the number of gamma and optical photons initiated. The optimal number of each varies with the detector specifics. In this work, we present a different simulation paradigm in which Geant4 was customized to allow for the user to specify the quantities of detected gammas, and detected opticals per gamma. These quantities were empirically shown to be constant over a small selection of different detector types. While work still needs to be done to explore the range of detectors for which this technique will work, we demonstrate a concept which brings added convenience and efficiency to FLS detector simulations.