Image Reconstruction from Asymmetrically Truncated Cone Beam Projections with Applications in Airport Security
With the tightening security guidelines, fully 3D cone beam CT scanners are gradually being introduced into airport checked-in baggage screening systems. This presents new requirements on the scanning speed of cone beam systems, which were originally developed with medical applications in mind. The mechanical motion of the gantry is the main bottle neck in increasing speed of measurements acquisition in state of the art cone beam scanners. Therefore in the new generation of the cone beam systems the mechanically rotating gantry was replaced by a stationary ring of sources, which can by quickly switched on and off by the on board electronics, and multiple stationary rings of detectors. While the new geometry is capable of nearly real time data acquisition it comes at the cost of asymmetrical axial truncation of the cone beam projections and hence incompleteness of the data. In this talk we discuss rebinning methods for reconstruction from such axially truncated projections: constraint optimal surface rebinning and a new family of methods, multi-sheet surface rebinning methods.