An accelerated 3D maximum likelihood SPECT image reconstruction

A three-dimensional maximum likelihood estimation (MLE) algorithm for single photon emission computed tomography (SPECT) image reconstruction is developed. This expectation maximization MLE algorithm is implemented using a projector-backprojector pair which approximates the two-dimensional, position-dependent blurring in SPECT. The resulting iterative algorithm is integrated with a recently developed acceleration scheme based on vector extrapolation techniques adapted to three dimensions. Using the minimal polynomial and reduced rank vector extrapolation techniques, the accelerated 3-D MLE algorithm is evaluated on patient data from a SPECT system. It is shown that the acceleration scheme results in substantial savings in computation time.<>