Department of Experimental Diagnostic Imaging, University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA.
J Nucl Med. 2012 Nov;53(11):1786-93. doi: 10.2967/jnumed.112.103507. Epub 2012 Sep 20.
The dedicated murine PET (MuPET) scanner is a high-resolution, high-sensitivity, and low-cost preclinical PET camera designed and manufactured at our laboratory. In this article, we report its performance according to the NU 4-2008 standards of the National Electrical Manufacturers Association (NEMA). We also report the results of additional phantom and mouse studies.
The MuPET scanner, which is integrated with a CT camera, is based on the photomultiplier-quadrant-sharing concept and comprises 180 blocks of 13 × 13 lutetium yttrium oxyorthosilicate crystals (1.24 × 1.4 × 9.5 mm(3)) and 210 low-cost 19-mm photomultipliers. The camera has 78 detector rings, with an 11.6-cm axial field of view and a ring diameter of 16.6 cm. We measured the energy resolution, scatter fraction, sensitivity, spatial resolution, and counting rate performance of the scanner. In addition, we scanned the NEMA image-quality phantom, Micro Deluxe and Ultra-Micro Hot Spot phantoms, and 2 healthy mice.
The system average energy resolution was 14% at 511 keV. The average spatial resolution at the center of the field of view was about 1.2 mm, improving to 0.8 mm and remaining below 1.2 mm in the central 6-cm field of view when a resolution-recovery method was used. The absolute sensitivity of the camera was 6.38% for an energy window of 350-650 keV and a coincidence timing window of 3.4 ns. The system scatter fraction was 11.9% for the NEMA mouselike phantom and 28% for the ratlike phantom. The maximum noise-equivalent counting rate was 1,100 at 57 MBq for the mouselike phantom and 352 kcps at 65 MBq for the ratlike phantom. The 1-mm fillable rod was clearly observable using the NEMA image-quality phantom. The images of the Ultra-Micro Hot Spot phantom also showed the 1-mm hot rods. In the mouse studies, both the left and right ventricle walls were clearly observable, as were the Harderian glands.
The MuPET camera has excellent resolution, sensitivity, counting rate, and imaging performance. The data show it is a powerful scanner for preclinical animal study and pharmaceutical development.
专用鼠 PET（MuPET）扫描仪是一种高分辨率、高灵敏度、低成本的临床前 PET 相机，由我们实验室设计和制造。本文根据美国国家电器制造商协会（NEMA）的 NU 4-2008 标准报告其性能。我们还报告了额外的体模和老鼠研究结果。
MuPET 扫描仪与 CT 相机集成，基于光电倍增管象限共享的概念，由 180 个 13×13 硅酸镥闪烁晶体（1.24×1.4×9.5mm3）和 210 个低成本 19mm 光电倍增管组成。相机有 78 个探测器环，轴向视野为 11.6cm，环直径为 16.6cm。我们测量了扫描仪的能量分辨率、散射分数、灵敏度、空间分辨率和计数率性能。此外，我们还扫描了 NEMA 图像质量体模、Micro Deluxe 和 Ultra-Micro Hot Spot 体模以及 2 只健康老鼠。
系统平均能量分辨率在 511keV 时为 14%。在视场中心的平均空间分辨率约为 1.2mm，使用分辨率恢复方法时，中心 6cm 视场的空间分辨率提高到 0.8mm，且仍保持在 1.2mm 以下。相机的绝对灵敏度为 350-650keV 能量窗口和 3.4ns 符合时间窗口时为 6.38%。NEMA 鼠样体模的系统散射分数为 11.9%，鼠样体模的散射分数为 28%。NEMA 鼠样体模的最大噪声等效计数率为 57MBq 时为 1100cps，65MBq 时为 352kcps。NEMA 图像质量体模可清晰观察到 1mm 可填充棒。Ultra-Micro Hot Spot 体模的图像也显示了 1mm 热棒。在老鼠研究中，左右心室壁以及哈氏腺均清晰可见。
MuPET 相机具有出色的分辨率、灵敏度、计数率和成像性能。数据表明，它是一种用于临床前动物研究和药物开发的强大扫描仪。
