Modeling and Reconstruction Strategy for Compton Scattering Tomography with Scintillation Crystals

The recent development of energy-resolved scintillation crystals opens the way to build novel imaging concepts based on the variable energy. Among them, Compton scattering tomography (CST) is one of the most ambitious concepts. Akin to Computerized Tomography (CT), it consists in probing the attenuation map of an object of interest using external ionizing sources but strives to exploit the scattered radiation as an imaging agent. For medical applications, the scattered radiation represents 70 to 80% when the energy of the source is larger than 100 keV and results from the Compton effect. This phenomenon stands for the collision of a photon with an electron and rules the change of course and loss of energy undergone by the photon. In this article, we propose a modeling for the scattered radiation assuming polychromatic sources such as 60Co and scintillation crystals such as LBC:Ce. Further, we design a general strategy for reconstructing the electron density of the target specimen. Our results are illustrated for toy objects.