A layered single-side readout depth of interaction time-of-flight-PET detector.
A layered single-side readout depth of interaction time-of-flight-PET detector.
复制标题
DOI：
10.1088/1361-6560/abd592
复制
发表时间：
2021-02-11
影响因子：
3.5
通讯作者：
Sabet H
中科院分区：
文献类型：
--
作者：
Bläckberg L;Sajedi S;El Fakhri G;Sabet H
我们正在探索一种基于闪烁器的PET探测器，它具有高灵敏度、DOI能力和定时分辨率的潜力，具有单侧读出。我们的设计结合了两个以前的概念：1）多个闪烁体阵列堆叠相对偏移，产生固有的DOI信息，但良好的定时性能还没有被证明与传统的光共享读出。2)与光检测器一对一耦合的单晶阵列，与其光共享对应物相比显示出上级定时性能，但缺乏DOI。交错设计的第一层一对一耦合到光电检测器阵列的组合可以提供DOI和定时分辨率，并且在此通过光传输模拟来评估该概念。结果表明：1）与抛光像素相比，交错配置中的未抛光晶体像素在所有度量上产生更好的性能，而不管读出方案如何。2)第一层的一对一读出允许使用单个阈值进行精确的DOI提取。信号幅度超过阈值的MPPC像素数量对应于交互层。这种方法对于传统的光共享读出是不可能的。3)在阈值为2个光学光子的情况下，与常规的一对一耦合非DOI检测器相比，具有一对一耦合的第一层的分层方法由于有效地减小了晶体厚度而改善了接近MPPC的定时。在4层设计中，每层观察到91、127、151和164 ps的单个检测器定时分辨率值，以与具有一对一耦合的单个阵列的148 ps进行比较。4)对于具有光共享的分层设计，由于每通道更高的信号，定时随着MPPC像素大小的增加而改善。总之，直接的DOI确定，良好的定时性能和相对简单的设计相结合，使所提出的概念有望DOI-TOF PET探测器。
We are exploring a scintillator-based PET detector with potential of high sensitivity, DOI capability, and timing resolution, with single-side readout. Our design combines two previous concepts: 1) Multiple scintillator arrays stacked with relative offset, yielding inherent DOI information, but good timing performance has not been demonstrated with conventional light sharing readout. 2) Single crystal array with one-to-one coupling to the photodetector, showing superior timing performance compared to its light sharing counterparts, but lacks DOI. The combination, where the first layer of a staggered design is coupled one-to-one to a photodetector array, may provide both DOI and timing resolution and this concept is here evaluated through light transport simulations. Results show that: 1) Unpolished crystal pixels in the staggered configuration yield better performance across all metrics compared to polished pixels, regardless of readout scheme. 2) One-to-one readout of the first layer allows for accurate DOI extraction using a single threshold. The number of MPPC pixels with signal amplitudes exceeding the threshold corresponds to the interaction layer. This approach was not possible with conventional light sharing readout. 3) With a threshold of 2 optical photons, the layered approach with one-to-one coupled first layer improves timing close to the MPPC compared to the conventional one-to-one coupling non-DOI detector, due to effectively reduced crystal thickness. Single detector timing resolution values of 91, 127, 151 and 164 ps were observed per layer in the 4-layer design, to be compared to 148 ps for the single array with one-to-one coupling. 4) For the layered design with light sharing, timing improves with increased MPPC pixel size due to higher signal per channel. In conclusion, the combination of straightforward DOI determination, good timing performance, and relatively simple design makes the proposed concept promising for DOI-TOF PET detectors.