CONTINUING EDUCATION Analytic and Iterative Reconstruction Algorithms in SPECT*

Images of the inside of the human body can be obtained noninvasively using tomographic acquisition and processing techniques. In particular, these techniques are commonly used to obtain images of a -emitter distribution after its administration in the human body. The reconstructed images are obtained given a set of their projections, acquired using rotating gamma cameras. A general overview of analytic and iterative methods of reconstruction in SPECT is presented with a special focus on filter backprojection (FBP), conjugate gradient, maximum likelihood expectation maximization, and maximum a posteriori expectation maximization algorithms. The FBP algorithm is faster than iterative algorithms, with the latter providing a framework for accurately modeling the emission and detection processes.