Integrated whole-body PET/MR technology continues to mature and is now extensively used in clinical settings. However, due to the special design architecture, integrated whole-body PET/MR comes with a few inherent limitations. Firstly, whole-body PET/MR lacks sensitivity and resolution for focused organs. Secondly, broader clinical access of integrated PET/MR has been significantly restricted due to its prohibitively high cost. The MR-compatible PET insert is an independent and removable PET scanner which can be placed within an MRI bore. However, the mobility and configurability of all existing MR-compatible PET insert prototypes remain limited. An MR-compatible portable PET insert prototype, dual-panel portable PET (DP-PET), has been developed for simultaneous PET/MR imaging. Using SiPM, digital readout electronics, novel carbon fiber shielding, phase-change cooling, and MRI compatible battery power, DP-PET was designed to achieve high-sensitivity and high-resolution with compatibility with a clinical 3-T MRI scanner. A GPU-based reconstruction method with resolution modeling (RM) has been developed for the DP-PET reconstruction. We evaluated the system performance on PET resolution, sensitivity, image quality, and the PET/MR interference. The initial results reveal that the DP-PET prototype worked as expected in the MRI bore and caused minimal compromise to the MRI image quality. The PET performance was measured to show a spatial resolution ≤ 2.5 mm (parallel to the detector panels), maximum sensitivity = 3.6% at the center of FOV, and energy resolution = 12.43%. MR pulsing introduces less than 2% variation to the PET performance measurement results. We developed a MR-compatible PET insert prototype and performed several studies to begin to characterize the performance of the proposed DP-PET. The results showed that the proposed DP-PET performed well in the MRI bore and would cause little influence on the MRI images. The Derenzo phantom test showed that the proposed reconstruction method could obtain high-quality images using DP-PET.

中文翻译：

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双面板便携式 PET (DP-PET) 的设计和系统评估


集成全身 PET/MR 技术不断成熟，现已广泛应用于临床。然而，由于特殊的设计架构，集成全身PET/MR存在一些固有的局限性。首先，全身 PET/MR 缺乏聚焦器官的灵敏度和分辨率。其次，由于其成本过高，综合 PET/MR 更广泛的临床应用受到了极大的限制。与 MR 兼容的 PET 插入件是一种独立且可拆卸的 PET 扫描仪，可以放置在 MRI 孔内。然而，所有现有的 MR 兼容 PET 插入原型的移动性和可配置性仍然有限。一款兼容 MR 的便携式 PET 插入原型，即双面板便携式 PET (DP-PET)，已开发用于同步 PET/MR 成像。 DP-PET 采用 SiPM、数字读出电子设备、新型碳纤维屏蔽、相变冷却和 MRI 兼容电池电源，旨在实现高灵敏度和高分辨率，并与临床 3-T MRI 扫描仪兼容。一种基于 GPU 的分辨率建模 (RM) 重建方法已被开发用于 DP-PET 重建。我们评估了系统在 PET 分辨率、灵敏度、图像质量和 PET/MR 干扰方面的性能。初步结果表明，DP-PET 原型在 MRI 孔中按预期工作，对 MRI 图像质量的影响最小。测量 PET 性能，显示空间分辨率 ≤ 2.5 mm（与探测器面板平行），FOV 中心的最大灵敏度 = 3.6%，能量分辨率 = 12.43%。 MR 脉冲给 PET 性能测量结果带来小于 2% 的变化。 我们开发了一种兼容 MR 的 PET 插入物原型，并进行了多项研究，以开始表征所提出的 DP-PET 的性能。结果表明，所提出的DP-PET在MRI孔中表现良好，对MRI图像的影响很小。 Derenzo 体模测试表明，所提出的重建方法可以使用 DP-PET 获得高质量图像。