The incorporation of organ uptake into dynamic SPECT (dSPECT) image reconstruction

Dynamic SPECT (dSPECT) is an image reconstruction method that is capable of determining the kinetic rates of various physiological processes regionally in three dimensions while still maintaining the simple acquisition protocol of a single, slow camera rotation. Through the use of constraints in a constrained least squares routine (C-LS), we are able to determine both the rate of tracer uptake, as well as the rate of washout over the acquisition time of the SPECT scan. In both computer simulations and experiments, the C-LS approach has been shown to reproduce quite accurately, both the spatial and temporal behaviour of activity distribution. In dynamic heart simulations including attenuation and Poisson noise, similarity values have been obtained ranging from 0.328 (single head, 180/spl deg/ rotation) to 0.476 (triple head, 180/spl deg/ rotation). Simple phantom experiments have provided even better results of between 0.911 and 0.992 (dual head, 90/spl deg/ rotation). In a preliminary patient study of renal dynamics, results have been comparable to planar imaging, but with increased contrast.