Dynamic Energy-Window Data Collection for Positron Emmission Tomography Camera

Recent efforts in improving the image of the PET camera are focusing at improving the `intrinsic´ detection resolution of the camera by using small detectors. However, such improvements have not been accompanied by the necessary corresponding improvement in counting statistics. As a result the high resolution image is noisy and the clinically `usable´ resolution is much worse than the `specification´ resolution measured with millions of counts collected on a point source. A new dynamic energy-window data collection method proposed by W. H. Wong has the potential to increase the true counts collected by multiple times to lower the image noise associated with high resolution images so that a better `usable´ resolution can be achieved in high resolution cameras. In addition, this method suppresses the overwhelming accidental coincidence noise at very high radioactivity so that the dynamic operating range of the camera can be expanded by several times to accommodate the required large injectior bolus for dynamic imaging. This paper presents the theoretical model calculations on this method. The calculations show that multiple times of increase in the collected counts is theoretically possible for any imaging procedures in whicih there is variation in radiation level during the data collection period.