Convolutional image reconstruction for quantitative single photon emission computed tomography

Abstract

Two image reconstruction algorithms were investigated. They are based on filtered backprojection and are useful when the tissue attenuation is considered to be uniform in the object. The first method uses a weighted backprojection, the weighting factor being determined in such a way that the photon attenuation is compensated with low noise propagation. The parameters involved in the convolution kernel and the correction function were determined by a computer iteration program. The second method, which is a simplified version of the first, uses conventional backprojection and takes a shorter computation time than the first method. The statistical noise of an image can be minimized by suitable positioning of the coordinate origin for the reconstruction. The theory of the 2 methods, their performance on statistical noise and some results of mathematical and experimental phantom studies are described.