The Siemens high-resolution research tomograph (HRRT - a dedicated brain PET scanner) is to this day one of the highest resolution PET scanners; thus, it can serve as useful benchmark when evaluating performance of newer scanners. Here, we report results from a cross-validation study between the HRRT and the whole-body GE SIGNA PET/MR focusing on brain imaging. Phantom data were acquired to determine recovery coefficients (RCs), % background variability (%BG), and image voxel noise (%). Cross-validation studies were performed with six healthy volunteers using [11C]DTBZ, [11C]raclopride, and [18F]FDG. Line profiles, regional time-activity curves, regional non-displaceable binding potentials (BPND) for [11C]DTBZ and [11C]raclopride scans, and radioactivity ratios for [18F]FDG scans were calculated and compared between the HRRT and the SIGNA PET/MR. Phantom data showed that the PET/MR images reconstructed with an ordered subset expectation maximization (OSEM) algorithm with time-of-flight (TOF) and TOF + point spread function (PSF) + filter revealed similar RCs for the hot spheres compared to those obtained on the HRRT reconstructed with an ordinary Poisson-OSEM algorithm with PSF and PSF + filter. The PET/MR TOF + PSF reconstruction revealed the highest RCs for all hot spheres. Image voxel noise of the PET/MR system was significantly lower. Line profiles revealed excellent spatial agreement between the two systems. BPND values revealed variability of less than 10% for the [11C]DTBZ scans and 19% for [11C]raclopride (based on one subject only). Mean [18F]FDG ratios to pons showed less than 12% differences. These results demonstrated comparable performances of the two systems in terms of RCs with lower voxel-level noise (%) present in the PET/MR system. Comparison of in vivo human data confirmed the comparability of the two systems. The whole-body GE SIGNA PET/MR system is well suited for high-resolution brain imaging as no significant performance degradation was found compared to that of the reference standard HRRT.

中文翻译：

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HRRT与SIGNA PET / MRI系统的PET组件之间的交叉验证研究，重点是神经成像

迄今为止，西门子高分辨率研究型断层扫描仪（HRRT-专用的脑部PET扫描仪）是最高分辨率的PET扫描仪之一。因此，它可以作为评估较新扫描仪性能的有用基准。在这里，我们报告了HRRT与专注于脑成像的全身GE SIGNA PET / MR之间的交叉验证研究结果。获取幻像数据以确定恢复系数（RCs​​），％背景变异性（％BG）和图像体素噪声（％）。使用[11C] DTBZ，[11C]雷氯必利和[18F] FDG与六名健康志愿者进行了交叉验证研究。计算并比较了HRRT和SIGNA PET的[11C] DTBZ和[11C] raclopride扫描的线谱图，区域时间-活动曲线，区域不可位移结合电位（BPND），以及[18F] FDG扫描的放射性比。 /先生。幻像数据显示，使用有序飞行时间（TOF）和TOF +点扩散函数（PSF）+过滤器的有序子集期望最大化（OSEM）算法重建的PET / MR图像显示，与那些热球相比，它们的RC相似使用带有Posson和OSF滤波器的普通Poisson-OSEM算法重建的HRRT获得的结果。PET / MR TOF + PSF重建显示了所有热球的最高RC。PET / MR系统的图像体素噪声明显较低。线轮廓显示了两个系统之间极好的空间一致性。BPND值显示[11C] DTBZ扫描的变异性小于10％，[11C]雷氯必利的变异性小于19％（仅基于一名受试者）。平均[18F] FDG与pons的比率显示出小于12％的差异。这些结果证明了在PET / MR系统中存在较低体素水平噪声（％）的RC方面，这两个系统具有可比的性能。体内人类数据的比较证实了这两个系统的可比性。全身GE SIGNA PET / MR系统非常适合高分辨率脑成像，因为与参考标准HRRT相比，没有发现明显的性能下降。