PT - JOURNAL ARTICLE AU - Berg, Eric AU - Zhang, Xuezhu AU - Bec, Julien AU - Judenhofer, Martin S. AU - Patel, Brijesh AU - Peng, Qiyu AU - Kapusta, Maciej AU - Schmand, Matthias AU - Casey, Michael E. AU - Tarantal, Alice F. AU - Qi, Jinyi AU - Badawi, Ramsey D. AU - Cherry, Simon R. TI - Development and Evaluation of mini-EXPLORER: A Long Axial Field-of-View PET Scanner for Nonhuman Primate Imaging AID - 10.2967/jnumed.117.200519 DP - 2018 Jun 01 TA - Journal of Nuclear Medicine PG - 993--998 VI - 59 IP - 6 4099 - http://jnm.snmjournals.org/content/59/6/993.short 4100 - http://jnm.snmjournals.org/content/59/6/993.full SO - J Nucl Med2018 Jun 01; 59 AB - We describe a long axial field-of-view (FOV) PET scanner for high-sensitivity and total-body imaging of nonhuman primates and present the physical performance and first phantom and animal imaging results. Methods: The mini-EXPLORER PET scanner was built using the components of a clinical scanner reconfigured with a detector ring diameter of 43.5 cm and an axial length of 45.7 cm. National Electrical Manufacturers Association (NEMA) NU-2 and NU-4 phantoms were used to measure sensitivity and count rate performance. Reconstructed spatial resolution was investigated by imaging a radially stepped point source and a Derenzo phantom. The effect of the wide acceptance angle was investigated by comparing performance with maximum acceptance angles of 14°–46°. Lastly, an initial assessment of the in vivo performance of the mini-EXPLORER was undertaken with a dynamic 18F-FDG nonhuman primate (rhesus monkey) imaging study. Results: The NU-2 total sensitivity was 5.0%, and the peak noise-equivalent count rate measured with the NU-4 monkey scatter phantom was 1,741 kcps, both obtained using the maximum acceptance angle (46°). The NU-4 scatter fraction was 16.5%, less than 1% higher than with a 14° acceptance angle. The reconstructed spatial resolution was approximately 3.0 mm at the center of the FOV, with a minor loss in axial spatial resolution (0.5 mm) when the acceptance angle increased from 14° to 46°. The rhesus monkey 18F-FDG study demonstrated the benefit of the high sensitivity of the mini-EXPLORER, including fast imaging (1-s early frames), excellent image quality (30-s and 5-min frames), and late-time-point imaging (18 h after injection), all obtained at a single bed position that captured the major organs of the rhesus monkey. Conclusion: This study demonstrated the physical performance and imaging capabilities of a long axial FOV PET scanner designed for high-sensitivity imaging of nonhuman primates. Further, the results of this study suggest that a wide acceptance angle can be used with a long axial FOV scanner to maximize sensitivity while introducing only minor trade-offs such as a small increase in scatter fraction and slightly degraded axial spatial resolution.