A common approach to image reconstruction for different applications of Compton cameras

A unified method for representation and calculation of the system matrix for Compton cameras has been proposed. The method defines first a photon interaction scheme in form of a logic photon state machine and then calculates the system matrix elements based on the transition probabilities for each state. Additionally uncertainties of the measurement can be taken into account in form of probability density distributions or, in case of simplifications, as scalars. The method provides a structured approach for the system matrix calculation which simplifies the software development process and the optimization of the computational performance. Additionally, the system matrix calculation is completely independent of the reconstruction algorithm itself. Therefore, the same code can be used for the reconstruction of the measured data collected with the different hardware and for different applications (i.e. medical imaging or homeland security).