KINETIC MODELING OF TEBOROXIME USING DYNAMIC SPECT IMAGING OF A CANINE MODEL

The tomographic utility of Tc-99m-labeled teboroxime has been limited because of its fast washout from the heart, which requires rapid data acquisitions that have not been feasible until the recent development of multidetector SPECT systems. Methods: Using a three-detector SPECT system to acquire dynamic tomographic data every 10.2 sec, we investig ated the potential of modeling the kinetics of teboroxime to develop a sensitive and quantitative measure of cardiac perfusion. Seven studie s were performed on four dogs; in three of the studies the LAD artery was occluded. The three-dimensional activity distributions were recons tructed and were corrected for attenuation using a transmission scan. Time-activity curves from the blood and tissue were fit to a two-compa rtment model with two-way exchange. Results: Performing attenuation co rrection during the reconstruction process affected the washin paramet er k(21) significantly (p < 0.0001). The washin parameter k(21) also d ecreased significantly (p < 0.002) when the LAD was occluded. Conclusi ons: The results indicate that the washin of teboroxime in myocardial tissue (k(21)) measured using dynamic SPECT imaging and kinetic modeli ng is an indicator of myocardial blood flow.