Filtered-based expectation ߞ Maximization algorithm for Emission computed tomography (ECT) image reconstruction

The goal of Emission computed tomography (ECT) is to reconstruct the distribution of the radioisotopes in the body by measuring the emitted photons. There is a growing realization for the importance of the functional information that is submitted by ECT and there are important advancements taking place, both in the instrumentation for data collection and in the computer methods for reconstruction images from the measured data. These methods are designed to solve the inverse problem known as “image reconstruction from set of projections.” A general overview of: Filtered Back-Projection (FBP) and (Expectation Maximization) EM algorithms of reconstruction in ECT are presented in this paper. The simulated results are compared using quality measurements for various test cases and conclusion is achieved. Through these simulated results, we have demonstrated that the EM algorithm with post-filter provides the best image quality and the small values of the quality measurements.