Research Of Collimator Design And Reconstruction Algorithms In MicroSPECT

The thesis focused on the subjects of collimator design andreconstruction algorithms in the system of our Micro-SPECT (also calledSmall Animal SPECT) under development. At the first, the simplest case of single-pinhole collimator was discussedand the cone-beam projection data derived by circular sampling was proved tobe complete for an exactly analytical reconstruction. A reconstructionalgorithm in its discrete form was also given out. So we concluded thatcircular sampling orbit is suitable for our system. After inducing alinear-system model, a new de-correlation method in frequency domain for 2Dcoded-aperture imaging was brought out,which is better than the well-knowndecoding method. Then in Part 4 analyse on 3D analytical algorithms, 3D iterativealgorithms and 3D directly inverse algorithms for reconstruction were madefor our Micro-SPECT. Projection data from both Monte-Carlo simulation andexperiments were used in 3D reconstruction to validate the algorithms and testthe properties of our systems with NTHT-URA collimators. Based on the above work, a principle for optimizing the coded-aperturecollimator was deduced finally. It showed that the collimator-designoptimization equals to SNR maximization in frequency domain, which is notof much complexity.