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

Dynamic SPECT (dSPECT) is an image reconstruction method capable of determi ning three dimensional regional estimates of physiological kinetic rates wh ile still maintaining the simple acquisition protocol of a single, slow cam era rotation. Through the use of inequality constraints in a least squares optimization routine, we are able to determine both the rate of tracer upta ke and subsequent tracer washout over the acquisition time of the SPECT sca n. Simulations modelling different camera acquisition geometries and with vari able dual exponential kinetic parameters and model complexity (eg, statisti cal noise, object attenuation) were performed. It was found that kinetic pa rameters were accurate to within 50% of the true values for the case of fas t uptake and slow washout for a single head acquisition and improved to wit hin 95% when acquired with a triple head camera. Experimental phantom tests corraborated these results and are shown to have an accuracy of about 90%. A preliminary patient study of renal dynamics has also been performed and compared with conventional planar dynamic imaging, Results from this study indicate that the dSPECT reconstruction method is able to determine kinetic information with accuracy comparable to that of conventional planar dynami c imaging methods while providing additional three dimensional time behavio ur information.