Maximizing the Useful Field of View of the microPET: Feasibility of Imaging Large Animals

MicroPET is a high resolution positron emission tomograph designed to image rodents or small primates. However, the ability to image multiple rodents simultaneously or larger primates such as the baboon would expand its potential applications. The aim of this study was to investigate the factors that determine the feasibility of using the full field of view of the microPET scanner with these applications in mind. Spatial resolution, scatter fraction and attenuation were measured throughout the FOV using phantoms to simulate multiple mice or a large primate brain. The results showed that it is feasible to image larger subjects using the microPET scanner. However, the increased attenuation and scatter require corrections for these effects to ensure quantitatively accurate imaging studies. The variation in spatial resolution throughout the FOV will also need to be taken into account when interpreting the images and methods to improve the uniformity of resolution require further development and evaluation.