A Statistical Analysis of Count Normalization Methods Used in Positron-Emission Tomography

As part of the Positron-Emission Tomography (PET) [1] reconstruction process, annihilation counts are normalized for photon absorption, detector efficiency and detector-pair duty-cycle. Several normalization methods of time-of-flight and conventional systems are analyzed mathematically for count bias and variance. The results of the study have some implications on hardware and software complexity and on image noise and distortion.