A direct sinogram-restoration method for fast image reconstruction in compact DOI-PET systems

In a recent study, we proposed a sophisticated data-processing technique for correcting parallax errors that we believe allows for different, more efficient, and cost-effective design strategies. In particular, we demonstrated with a conceptual design the general feasibility of adopting this approach for the construction of compact positron emission tomography (PET) systems. In our design, we employed the new-generation depth-of-interaction detectors in a circular, highly compact PET system to generate imperfect, but redundant, data. The redundancy was exploited by sinograin restoration (SR) techniques to correct for the data imperfection, thereby obtaining high-quality PET images despite the use of a compact PET configuration. In this paper, we consider the specific task of applying the proposed design concept for building a dedicated, compact, small-animal PET system. We develop a direct SR method that is suitable for use in the small-animal system. We evaluate the performance of this conceptual design with computer simulations. Our results indicate that, with the effects of scatter and randoms ignored, the proposed design can produce images of quality comparable to those generated by a conventional larger ring system.