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内容記述 |
Sub-second dynamic PET imaging is important for preclinical research as cardiac, or brain functions change in sub-second scale order. However, the temporal resolution of conventional small animal PET scanners has been limited to the order of a few seconds at best due to low sensitivity. Here, we present an ultrasensitive small-animal PET scanner with total-body coverage of a rat for sub-second dynamic imaging. The developed total-body small-animal (TBS) PET scanner has a 155 mm inner diameter and 325.6 mm axial coverage. The PET scanner has 6 rings, each of which has 10 depth-of-interaction (DOI) detectors. Each DOI detector consists of a 4-layer Zr-doped gadolinium oxyorthosilicate crystal array (2.85 mm pitch, 30 mm total thickness) and 8×8 multi-anode photomultiplier tubes. The physical PET performance was evaluated based on the National Electrical Manufacturers Association NU4 protocol. The peak absolute sensitivity was 20.2% with an energy window of 400-600 keV. The 2.2 mm rod structure of the resolution phantom was resolved using an iterative algorithm. Total-body images of a rat were obtained with a single bed position. The cardiac function of a rat was visualized with 0.25 s temporal resolution, which was hardly possible with conventional small animal PET scanners. In conclusion, the developed TBS-PET enabled sub-second dynamic PET imaging in rodent models with total-body coverage. |
