小动物正电子断层成像仪性能测试

Performance evaluation of the microPET system

设计了一系列实验对Concorde Micro PETRodent R4小动物正电子断层成像系统(该系统是Concorde Microsystems公司开发的小动物专用PET扫描仪,该扫描仪具有32层探测器环,动物入口孔径为120mm,横向视野为100mm,轴向深度为78mm,标称的视野中央处的空间分辨率可达1.8mm以下)的空间分辨率、灵敏度、散射率等性能参数进行了测试,测试结果显示该扫描仪视野中心的横向空间分辨率为1.9mm,轴向空间分辨率为1.88mm,在能窗设定为250-750keV时系统的绝对灵敏度为39.88cps/kBq,同样能窗下二维重建散射分数为50.6%,三维重建散射分数为32.3%.

The Concorde MicroPET Rodent R4 system designed by Concorde Microsystems Inc. is the dedicated positron emission tomography （ECT） for studies of rodents. The scanner has 32 detector rings and a 120mm animal aperture. The transversal field of view（FOV） is 100mm, and the axial FOV is 78 mm. The spatial resolution at the center of FOV is smaller than 1.8 mm. This paper designs a series of experiments to evaluate the performance parameters （spatial resolution, sensitivity, scatter ets. ） of the scanner. In the center FOV the transversal spatial resolution is 1 .gmm, the axial spatial resolution is 1.88mm. The absolute sensitivity of the system is 39.88 cps/kBq for an energy window of 250KeV-750KeV. For the same energy window the 2D-reconstructed scatter fractions is 50.6%, the 3D-reconstructed scatter fractions is 32.3 %.