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内容記述 |
In a previous study, we developed a mouse brain dedicated positron emission tomography (PET) scanner using a staggered 3-layer depth-of-interaction (DOI) detector employing a 1 mm crystal pitch to achieve high resolution while minimizing the parallax error. However, the resolution was limited to around 0.6 mm due to unoptimized crystal pitch and layer design. In this study, following our simulation study presented in IEEE MIC 2024, we developed a new small animal PET scanner to achieve sub-0.5 mm resolution for mouse brain imaging. The developed small animal PET scanner had a 48 mm inner diameter and 23.4 mm axial FOV. The LYSO crystal array had the pixel pitch of 0.8 mm and total thickness of 11 mm. The PET scanner consisted of 2 rings each of which had 16 DOI detectors. Each DOI detector consisted of a 3-layer staggered LYSO crystal array and 5×5 SiPM array with a pixel pitch of 2.4 mm. The SiPM anode signals were multiplexed using a resistive network and then digitized by a custom-made DAQ. The respective measured spatial resolutions at the center and 5 mm radial offset were 0.68 mm and 0.71 mm for the FBP algorithm. The 0.45 mm rod structures of a resolution phantom were resolved using the OSEM algorithm. The in vivo mouse brain imaging showed detailed mouse brain structures, which were barely resolved with conventional preclinical PET scanners. In summary, we successfully developed the new mouse brain PET scanner that can provide sub-0.5 mm resolution. In the near future, we will use the developed PET for neuroscience research with disease rodent models. |
