NEMA NU-04-based performance characteristics of the LabPET-8™ small animal PET scanner
NEMA NU-04-based performance characteristics of the LabPET-8™ small animal PET scanner
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DOI：
10.1088/0031-9155/56/20/009
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发表时间：
2011-10-21
影响因子：
3.5
通讯作者：
Zaidi, Habib
中科院分区：
文献类型：
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作者：
Prasad, Rameshwar;Ratib, Osman;Zaidi, Habib
本研究的目的是使用美国国家电气制造商协会（NEMA）NU 04-2008协议表征完全集成的三模态PET/SPECT/CT Triumph（TM）扫描仪的基于雪崩光电二极管（APD）的临床前LabPET-8（TM）子系统的性能。表征的性能参数包括空间分辨率、灵敏度、散射分数、计数率性能和图像质量特性。PET系统是完全数字化的，使用基于APD的探测器模块和高度集成的电子器件。探测器组件由Lu（1.9）Y（0.1）SiO（5）（LYSO）和Lu（0.4）Gd（1.6）SiO（5）（LGSO）晶体的phoswich对组成，尺寸为2 x 2 x 14 mm（3），具有7.5 cm轴向和10 cm横向视场（FOV）。在扫描仪的FOV中的不同位置处使用小（22）Na点源测量空间分辨率和灵敏度。散射分数和计数率的特点，使用小鼠和大鼠大小的幻影与（18）F线源安装测量。使用NEMA图像质量体模和实验室动物研究评估扫描仪的整体成像能力。基于NEMA的径向和切向空间分辨率范围分别为：FOV中心的1.7 mm至径向偏移2.5 cm时的2.59 mm，以及FOV中心的1.85 mm至径向偏移2.5 cm时的1.76 mm。迭代重建将FOV中心的空间分辨率提高到0.84 mm。在250-650 keV的能量窗口内，系统总的绝对灵敏度为12.74%。对于小鼠大小的体模，峰值噪声等效计数率（NECR）在2.07 MBq cc（-1）时为183 kcps，而峰值真实计数率在2.5 MBq cc（-1）时为320 kcps，散射分数为19%。大鼠大小的体模的散射分数为31%，在0.23 MBq cc（-1）时的峰值NECR为67 kcps，在0.27 MBq cc（-1）时的峰值真实计数率为186 kcps。平均放射性浓度为126.97kBq·ml ~（-1），标准偏差为7%。LabPET-8（TM）扫描仪的性能基于NEMA NU 04-2008标准进行表征。LabPET-8（TM）系统的所有性能表明，它能够在合理的时间内生成高质量和高对比度的图像，因此非常适合临床前分子成像研究。
The objective of this study is to characterize the performance of the preclinical avalanche photodiode (APD)-based LabPET-8 (TM) subsystem of the fully integrated trimodality PET/SPECT/CT Triumph (TM) scanner using the National Electrical Manufacturers Association (NEMA) NU 04-2008 protocol. The characterized performance parameters include the spatial resolution, sensitivity, scatter fraction, counts rate performance and image-quality characteristics. The PET system is fully digital using APD-based detector modules with highly integrated electronics. The detector assembly consists of phoswich pairs of Lu(1.9)Y(0.1)SiO(5) (LYSO) and Lu(0.4)Gd(1.6)SiO(5) (LGSO) crystals with dimensions of 2 x 2 x 14 mm(3) having 7.5 cm axial and 10 cm transverse field of view (FOV). The spatial resolution and sensitivity were measured using a small (22)Na point source at different positions in the scanner's FOV. The scatter fraction and count rate characteristics were measured using mouse-and rat-sized phantoms fitted with an (18)F line source. The overall imaging capabilities of the scanner were assessed using the NEMA image-quality phantom and laboratory animal studies. The NEMA-based radial and tangential spatial resolution ranged from 1.7 mm at the center of the FOV to 2.59 mm at a radial offset of 2.5 cm and from 1.85 mm at the center of the FOV to 1.76 mm at a radial offset of 2.5 cm, respectively. Iterative reconstruction improved the spatial resolution to 0.84 mm at the center of the FOV. The total absolute system sensitivity is 12.74% for an energy window of 250-650 keV. For the mouse-sized phantom, the peak noise equivalent count rate (NECR) is 183 kcps at 2.07 MBq cc(-1), whereas the peak true count rate is 320 kcps at 2.5 MBq cc(-1) with a scatter fraction of 19%. The rat-sized phantom had a scatter fraction of 31%, with a peak NECR of 67 kcps at 0.23 MBq cc(-1) and a peak true count rate of 186 kcps at 0.27 MBq cc(-1). The average activity concentration and percentage standard deviation were 126.97 kBq ml(-1) and 7%, respectively. The performance of the LabPET-8 (TM) scanner was characterized based on the NEMA NU 04-2008 standards. The all in all performance demonstrates that the LabPET-8 (TM) system is able to produce high-quality and highly contrasted images in a reasonable time, and as such it is well suited for preclinical molecular imaging-based research.