Image reconstruction in rectangular PET systems using distance-driven projections

An image reconstruction algorithm for rectangular PET scanner was developed using distance-driven projections. The geometrical sensitivity of the tubes of response in rectangular geometry was derived under the assumption that the detector area is very small relative to the distances between the detectors. Linograms were used for the histograms of coincidences between parallel panels, and “orthograms” were proposed for the histograms of orthogonal panels. Open Gate was used to simulate a box-shaped PET scanner for projections of hot rod and flood phantoms. The reconstructed images from simulated projections demonstrated feasibility of the proposed method.