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内容記述 |
For mouse brain PET imaging with high quantification accuracy, spatial resolution is the most important parameter. However, the spatial resolution of PET has been limited to over 0.5 mm for the last two decades. Here we report on a mouse brain PET design that can achieve sub-0.5 mm resolution. The developed PET scanner has a 48 mm ring diameter and 23.4 mm axial field of view. The PET scanner consists of 32 depth-of-interaction (DOI) detectors. Each DOI detector consists of a staggered 3-layer LYSO crystal array (crystal pitch=0.8 mm, total thickness= 11 mm) and silicon photomultipliers 5×5 array with a 2.4 mm pixel pitch. The physical performance of the PET scanner was evaluated according to the National Electrical Manufacturers Association NU4 protocol. In vivo mouse brain imaging was performed with 18F-FITM radiotracer. The peak axial sensitivity was 0.65% with an energy window of 440-560 keV. The spatial resolution was 0.67 mm with filtered back projection at the center. With iterative reconstruction algorithm, the 0.45 mm rod structures were clearly resolved with an average valley-to-peak ratio of 0.655±0.071. The mouse brain structures such as thalamus, hypothalamus, and cerebellum were clearly visualized. In conclusion, the developed mouse brain PET scanner achieved sub-0.5 mm resolution thereby visualizing mouse brain function in detail. |
