Purpose We developed a low-complexity,high-resolution depth-of-interaction(DOI)capable positron emission tomography(PET)detector and tested its performance to prove that it can be applied to practical PET instruments....Purpose We developed a low-complexity,high-resolution depth-of-interaction(DOI)capable positron emission tomography(PET)detector and tested its performance to prove that it can be applied to practical PET instruments.Methods The detector module consists of a 24×24 LYSO crystal matrix,each with dimension of 1.04×1.04×15mm^(3),optically coupled to an 8×8 SiPM photo-sensor array with TOFPET2 ASIC single-ended readout.By only adding a light guide at the top of the crystal to reflect scintillation light back to the SiPM array,the continuous DOI information is extracted using a light sharing and redirection encoding method without adding system complexity.Results The crystal array with 9-to-1 coupling between scintillators and photo-sensors can be clearly separated in the flood image.The other detector performance in terms of DOI resolution,energy resolution and coincidence time resolution are measured on average as 4.1 mm,15.0%and 432 ps,respectively.Conclusion The test results confirm that the light sharing and redirection DOI encoding method can provide reasonably high DOI resolution without deteriorating other performance,even for highly pixelated PET detectors readout with commercially available ASIC chip.It has great potential for applications in future pre-clinical and organ-dedicated PET scanners.展开更多
In this work we studied the feasibility of detecting the depth of interaction （DOI） with two layers of crystal arrays of LYSO and BGO scintillators coupled to a position-sensitive photomultiplier tube （PS-PMT） R89...In this work we studied the feasibility of detecting the depth of interaction （DOI） with two layers of crystal arrays of LYSO and BGO scintillators coupled to a position-sensitive photomultiplier tube （PS-PMT） R8900-C12. A front-end electronics was designed, with which we got different pulse shapes for different crystals to obtain depth information. With the double integration method, we got the DOI histogram of a divided integration ratio of two crystals as the standard to determine the layer-of-interaction. The DOI accuracy, measured by scanning a 22Na slit source along the side of the module, was 98% for the LYSO layer and 95% for the BGO layer. The energy resolution at 511keV was 13.1% for LYSO and 17.1% for BGO. We obtained good crystal separation in 2D position histograms of both layers. These results could be useful in the manufacture of PET scanners with high spatial resolutions.展开更多
基金This work was supported by the National Natural Science Foundation of China[Grant Number 11735013].
文摘Purpose We developed a low-complexity,high-resolution depth-of-interaction(DOI)capable positron emission tomography(PET)detector and tested its performance to prove that it can be applied to practical PET instruments.Methods The detector module consists of a 24×24 LYSO crystal matrix,each with dimension of 1.04×1.04×15mm^(3),optically coupled to an 8×8 SiPM photo-sensor array with TOFPET2 ASIC single-ended readout.By only adding a light guide at the top of the crystal to reflect scintillation light back to the SiPM array,the continuous DOI information is extracted using a light sharing and redirection encoding method without adding system complexity.Results The crystal array with 9-to-1 coupling between scintillators and photo-sensors can be clearly separated in the flood image.The other detector performance in terms of DOI resolution,energy resolution and coincidence time resolution are measured on average as 4.1 mm,15.0%and 432 ps,respectively.Conclusion The test results confirm that the light sharing and redirection DOI encoding method can provide reasonably high DOI resolution without deteriorating other performance,even for highly pixelated PET detectors readout with commercially available ASIC chip.It has great potential for applications in future pre-clinical and organ-dedicated PET scanners.
基金Supported by National Natural Science Foundation of China (10805049, 10775149)
文摘In this work we studied the feasibility of detecting the depth of interaction （DOI） with two layers of crystal arrays of LYSO and BGO scintillators coupled to a position-sensitive photomultiplier tube （PS-PMT） R8900-C12. A front-end electronics was designed, with which we got different pulse shapes for different crystals to obtain depth information. With the double integration method, we got the DOI histogram of a divided integration ratio of two crystals as the standard to determine the layer-of-interaction. The DOI accuracy, measured by scanning a 22Na slit source along the side of the module, was 98% for the LYSO layer and 95% for the BGO layer. The energy resolution at 511keV was 13.1% for LYSO and 17.1% for BGO. We obtained good crystal separation in 2D position histograms of both layers. These results could be useful in the manufacture of PET scanners with high spatial resolutions.
文摘采用主动式光电倍增管分压电路,通过改变分压电路中电阻和电容的参数值,调节PMT级间电压,以优化输出信号的性能;利用MATLAB编程,控制高频示波器采集信号的形状,对这些数值信号形状数据进行拟合计算,得到信号的平均上升时间,通过不断改变电路元件参数值,对比分析结果,得到分压电路最优的元件工作参数,使PET系统的时间分辨从397 ps上升到359 ps.
