Look-up table-based simulation of scintillation detectors in computed tomography

The design of a CT detector requires a precise detector model, since building prototypes for many different proposed detector geometries is too costly. We introduce a look-up table-based simulation of scintillation detectors on X-ray photon level. It uses energy-resolved sinograms of incoming X-ray intensities as input data and generates photon counts for each channel and reading. The effects of X-ray- and optical cross-talk, temporal cross-talk between readings, Poisson noise and electronics effects are covered. The photon interaction data as well as optical cross-talk distribution are provided in the form of detector specific look-up tables. Unlike standard Monte-Carlo simulations of X-ray interaction processes, our approach is capable of simulating whole sinograms in a reasonable amount of time and still offers a very high precision of the detector model. This way the influence of detector effects can be investigated in the reconstructed image data. The simulation is verified against data measured with a CT scanner and data from a fully single photon-based Monte-Carlo simulation in terms of image modulation transfer function (MTF) and detector noise power spectrum (NPS).