PennPET Explorer: Design and Preliminary Performance of a Whole-body Imager

Abstract

We report on the development of the PennPET Explorer whole-body imager. Methods: The PennPET Explorer is a multi-ring system designed with a long axial field-of-view (AFOV). The imager is scalable and comprises multiple 22.9-cm long ring-segments, each with 18 detector modules based on the digital Philips Digital Photon Counting (PDPC) silicon photomultiplier. A prototype three-segment imager has been completed and tested with an active 64-cm AFOV. Results: The instrument design is described, and its physical performance measurements are presented. These include sensitivity of 55 kcps/MBq, spatial resolution of 4.0 mm, energy resolution of 12%, timing resolution of 250 ps, and a noise equivalent count rate above 1000 kcps beyond 30 kBq/cc. Following an evaluation of lesion torso phantoms to characterize the imager’s quantitative accuracy, human studies were performed on normal volunteers. Conclusion: The physical performance measurements validate the system design and lead to the high quality human studies. A more detailed examination of human imaging with this whole-body imager is presented in a companion paper.