Integration of advanced 3D SPECT modeling into the open-source STIR framework

Purpose: The Software for Tomographic Image Reconstruction (STIR,http://stir.sourceforge.net) package is an open source object-oriented library implemented in C++. Although its modular design is suitable for reconstructing data from several modalities, it currently only supports Positron Emission Tomography (PET) data. In this work, the authors present results for Single Photon Emission Computed Tomography (SPECT) imaging. Methods: This was achieved by the complete integration of a 3D SPECT system matrix modeling library into STIR. Results: The authors demonstrate the flexibility of the combined software by reconstructing simulated and acquired projections from three different scanners with different iterative algorithms of STIR. Conclusions: The extension of the open source STIR project with advanced SPECT modeling will enable the research community to study the performance of several algorithms on SPECT data, and potentially implement new algorithms by expanding the existing framework.