Kinetic parameter estimation from dynamic cardiac patient SPECT projection measurements

The estimation of kinetic parameters directly from projection data is potentially useful for clinical dynamic cardiac SPECT studies, particularly those using a single detector system or body contouring orbits with a multi-detector system. A dynamic image sequence reconstructed from the inconsistent projections acquired by a relatively slowly rotating gantry can contain artifacts that lead to biases in kinetic parameters estimated from time-activity curves generated by overlaying regions of interest on the images. Using simulated data we have shown that unbiased kinetic parameter estimates can be obtained directly from the projections. Here we present results of a ^99m Tc-teboroxime patient study where the regions of the left ventricular myocardium, blood pool, liver, and background tissue were determined by automatically segmenting a dynamic image sequence reconstructed from the inconsistent projection data. A spatial model for the projections was then created and one compartment kinetic model parameters for the myocardium and liver were estimated directly from the projections