Timing resolution improvement using DOI information in a four-layer scintillation detector for TOF-PET
Timing resolution improvement using DOI information in a four-layer scintillation detector for TOF-PET
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DOI：
10.1016/j.nima.2008.05.020
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发表时间：
2008-08-11
影响因子：
1.4
通讯作者：
Murayama, Hideo
中科院分区：
文献类型：
--
作者：
Shibuya, Kengo;Nishikido, Fumihiko;Murayama, Hideo
相互作用深度（DOI）检测器被认为对于飞行时间正电子发射断层摄影（TOF-PET）是有利的，因为它们可以校正由于湮灭辐射和闪烁光子之间的传播速度差而在闪烁晶体中出现的定时误差。我们通过实验测量了这种定时误差，使用我们的四层DOI编码方法。上层表现出较大的定时延迟，这是由于在从湮灭辐射转换成闪烁光子之后的较长路径长度，闪烁光子以折射率（n）的因子减小的速度通过Z字形路径行进。当n = 1.47时，最上层和最下层之间的最大定时延迟被评估为164 ps。TOF误差校正被证明可以将四层DOI探测器的定时分辨率提高10.3%，与非DOI TOF-PET扫描仪相比，这将使扫描仪的有效灵敏度提高约12%。这是将PET仪器中的这两个重要领域（即DOI和TOF）结合起来的第一步，目的是实现更高的灵敏度以及更均匀的空间分辨率。(C)2008 Elsevier B. V.保留所有权利。
Depth-of-interaction (DOI) detectors are considered to be advantageous for time-of-flight positron emission tomography (TOF-PET) because they can correct timing errors arising in the scintillation crystals due to a propagation speed difference between annihilation radiation and scintillation photons. We experimentally measured this timing error, using our four-layer DOI encoding method. The upper layers exhibited the larger timing delays due to the longer path lengths after conversion from annihilation radiation into scintillation photons that traveled by zigzag paths at a speed decreased by a factor of the refractive index (n). The maximum timing delay between the uppermost and the lowermost layers was evaluated as 164 ps when n = 1.47. A TOF error correction was demonstrated to improve the timing resolution of the four-layer DOI detector by 10.3%, which would increase the effective sensitivity of the scanner by about 12% comparison with a non-DOI TOF-PET scanner. This is the first step towards combining these two important fields in PET instrumentation, namely DOI and TOF, for the purpose of achieving a higher sensitivity as well as a more uniform spatial resolution. (C) 2008 Elsevier B.V. All rights reserved.