ECAT III -- Basic Design Considerations

The ECAT III is a whole body positron tomograph which has been designed in a collaborative effort between investigators at UCLA and EGandG/Ortec (Oak Ridge, Tennessee). The primary emphasis in the design has been on the problems of imaging the heart. In our experience with the ECAT II at UCLA, the primary problems in heart imaging were: 1) gated studies of the heart would have serious image artifacts if the scanning period was too short, and 2) the resolution of the system made quantitative measurements difficult, particularly in those cases in which there was significant activity in the blood pool. In this communication, we will briefly describe the ECAT III and then present some of the theoretical and experimental data which influenced the design.