Effect of increased axial field of view on the performance of a volume PET scanner

The performance of the PENN-PET (positron emission tomography) 240H scanner from UGM Medical Systems is tested and compared to the prototype PENN-PET scanner built at the University of Pennsylvania. The UGM PENN-PET scanner consists of six continuous position-sensitive NaI(Tl) detectors, which results in a 50-cm transverse field-of-view and a 12.8-cm axial field-of-view. The fine spatial sampling in the axial direction allows the data to be sorted into as many as 64 transverse planes, each 2-mm thick. A large axial acceptance angle, without interplane septa, results in a high sensitivity, with a low scatter and random fraction, due to the use of a narrow photopeak energy window. Emphasis is placed on those performance measurements that illustrate the special characteristics of a volume imaging scanner and how they change as the axial length is increased.<>