IEEE Trans Med Imaging. 2016 Aug;35(8):1907-14. doi: 10.1109/TMI.2016.2537811. Epub 2016 Mar 9.
A recent entry into the rapidly evolving field of integrated PET/MR scanners is presented in this paper: a whole body hybrid PET/MR system (SIGNA PET/MR, GE Healthcare) capable of simultaneous acquisition of both time-of-flight (TOF) PET and high resolution MR data. The PET ring was integrated into an existing 3T MR system resulting in a (patient) bore opening of 60 cm diameter, with a 25 cm axial FOV. PET performance was evaluated both on the standalone PET ring and on the same detector integrated into the MR system, to assess the level of mutual interference between both subsystems. In both configurations we obtained detector performance data. PET detector performance was not significantly affected by integration into the MR system. The global energy resolution was within 2% (10.3% versus 10.5%), and the system coincidence time resolution showed a maximum change of < 3% (385 ps versus 394 ps) when measured outside MR and during simultaneous PET/MRI acquisitions, respectively. To evaluate PET image quality and resolution, the NEMA IQ phantom was acquired with MR idle and with MR active. Impact of PET on MR IQ was assessed by comparing SNR with PET acquisition on and off. B0 and B1 homogeneities were acquired before and after the integration of the PET ring inside the magnet. In vivo brain and whole body head-to-thighs data were acquired to demonstrate clinical image quality.
本文介绍了一种最新的集成正电子发射断层扫描/磁共振成像（PET/MR）扫描仪：全身型混合 PET/MR 系统（SIGNA PET/MR，GE 医疗），能够同时采集飞行时间（TOF）PET 和高分辨率磁共振数据。该 PET 环集成到现有的 3T MR 系统中，结果是（患者）孔径为 60 厘米，轴向视野为 25 厘米。在单独的 PET 环和集成到 MR 系统中的相同探测器上评估了 PET 性能，以评估两个子系统之间的相互干扰程度。在这两种配置中，我们都获得了探测器性能数据。PET 探测器性能并未因集成到 MR 系统中而受到显著影响。整体能量分辨率在 2%以内（10.3%与 10.5%），当在 MR 之外和同时进行 PET/MRI 采集时测量时，系统符合时间分辨率的最大变化<3%（385 ps 与 394 ps）。为了评估 PET 图像质量和分辨率，使用 MR 空闲和 MR 活动采集了 NEMA IQ 体模。通过比较有和无 PET 采集时的 SNR 来评估 PET 对 MR IQ 的影响。在将 PET 环集成到磁体内部之前和之后，采集了 B0 和 B1 均匀性。采集了用于演示临床图像质量的活体大脑和全身到头大腿数据。
