Bryan Reutter
10:00, Saturday September 21, 2002
Compartmental Modeling from Dynamic Cardiac Patient SPECT Projections

We present compartmental modeling results for a Tc-99m-teboroxime patient study. Surface models for the left ventricular myocardium, blood pool, liver, and background tissue were determined by automatic 4-D segmentation of late time frames in a conventional dynamic image reconstruction. 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 projection data. Kinetic parameters were also obtained "semi-directly" by first estimating spline time-activity curve models for the segmented volumes directly from the projection data and then fitting one-compartment models to the curves. The two approaches yielded comparable results and the semi-direct approach was faster. These methods provided better separation of activities in the segmented volumes compared to an analysis in which time-activity curves were obtained by overlaying the volumes on a conventional dynamic image reconstruction. The relation of this work to other methods such as factor analysis of dynamic structures is described and future directions are proposed.