3D Compton Imaging based on Changeable Space Reconstruction

Compton imaging is a promising imaging technique which can be used in homeland security and medical imaging. Room temperature CZT detector is an excellent candidate for the implementation of Compton imaging. Due to the small size of CZT detector, 3D reconstruction using a single stationary-detector array can only be implemented in the vicinity of the detector [1]. As for the imaging in the far-field area, because the small change of vertices of Compton cones among the detector volume is negligible, all these vertices will be considered at the origin of the imaging sphere, which means we can only know the directional distribution of radioactive sources. So the key point for a real 3D reconstruction in the far-field area is to provide enough parallax during the measurement. In this article, we used a single moving detector array to create the parallax necessary for the reconstruction in the 3D space in the vicinity of detector path, and a changeable space reconstruction method was proposed to decrease the computational and storage difficulties caused by the large size of 3D image space. Simulation and experiment were done to verify the feasibility of this method.