Mesh model based projection operator for emission tomography

In this paper, we presented a framework for calculation of a projection operator for emission tomographic reconstruction, using content-adaptive mesh model (CAMM) for image representation, which can incorporate major image degradation models, namely attenuation and parallel hole collimator response. The CAMM is an efficient image description based on non-uniform sampling and linear interpolation. The data acquisition process, e.g. forward projection, is calculated using a ray-casting algorithm. We tested, successfully, the proposed projection operator model using a simulation and a maximum-likelihood expectation maximization reconstruction algorithm. The research described in this paper establishes a methodology for future development of 4D (deformable) CAMM reconstruction.