Standardize Angular Response Function Pre-calculation Requirements for Collimator-Detector Response Modeling in SPECT Imaging

Abstract

Photon-tracking Monte Carlo simulations of Single Photon Emission Computed Tomography (SPECT) are inherently inefficient. One proposal to speed such simulations is to use Angular Response Functions (ARFs) to model the collimator-detector response. Unfortunately, generation of ARFs is also extremely computation intensive: a table is needed for each incident energy, for each collimator/detector combination, and for each energy window of interest. The method is only useful when the same collimator/detector/energy window combination will be used for a large number of simulations. In this thesis we report on a systematic way to reduce the number of tables needed, and the number of photons needed to generate a table. We first introduce the background of SPECT imaging system and the Monte Carlo simulation method. We then focus on the generation of ARFs for 67Ga and their implications for quantitative imaging. We incorporated the ARF feature to our public domain emission tomography simulation SimSET and validate the simulation results by comparing with the experiment results under same configuration. Our method is feasible for a wider range of application.