A true three-dimensional reconstruction algorithm for the spherical positron emission tomograph

Abstract

A spherical detector configuration in truncated form, consisting of multiple layers of ring detector arrays, can substantially improve the reconstructed image quality in positron emission tomography since all inclined annihilation photon rays can now be used for reconstruction of the image. A new true three-dimensional reconstruction (TTR) algorithm suitable for spherical and quasi-spherical forms of detector arrays is presented. In this algorithm each set of two-dimensional projection data is filtered with a 2-D filter function appropriate to the angular orientations, then back-projected onto the object space in every direction. An example of statistical image quality improvement for this algorithm over the conventional two-dimensional algorithm using only intraplane rays is presented using computer simulation.