A depth-of-interaction PET detector using a stair-shaped reflector arrangement and a single-ended scintillation light readout
A depth-of-interaction PET detector using a stair-shaped reflector arrangement and a single-ended scintillation light readout
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DOI：
10.1088/1361-6560/aa5076
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发表时间：
2017-01-21
影响因子：
3.5
通讯作者：
Lee, Jae Sung
中科院分区：
文献类型：
--
作者：
Son, Jeong-Whan;Lee, Min Sun;Lee, Jae Sung
正电子发射断层扫描(PET)探测器具有编码相互作用深度(DOI)信息的能力，使我们能够同时提高PET扫描仪的空间分辨率和灵敏度。在这项研究中，我们提出了一种基于阶梯图案反射器的DOI PET探测器，该探测器插入在像素化晶体和单端闪烁光读出之间。该方法的主要优点是简单；DOI信息从洪水图中解码，数据可以通过单端读出系统简单地获取。另一个潜在的优势是，两步DOI检测器可以在洪水图中提供最大的峰值位置距离，因为二维峰值位置可以均匀分布。我们进行了蒙特卡罗模拟，得到了洪水图。然后，我们使用截面为1.7x1.7 mm(2)的5x5Lu1.9Y0.1SiO5：Ce晶体的两步DOI阵列和不同的探测器配置进行了实验研究：未抛光的单层(US)阵列、抛光的单层(PS)阵列和抛光的堆叠两层(PT)阵列。对于每种探测器配置，都测试了空气间隙和室温硫化(RTV)硅胶间隙。US和PT探测器在每个闪烁体中表现出良好的峰分离，平均峰谷比(PVR)和距离宽度比(DWR)分别为2.09和1.53。PSRTV显示较低的PVR和DWR(分别为1.65和1.34)。由于与非DOI探测器相比，时间分辨率仅降低了约40ps，因此探测器PTAir的配置更适合于构建飞行时间-DOI探测器。USAIR和PSRTV探测器的性能低于非DOI探测器，因此在制造成本比定时性能更重要的情况下，这些设计是有利的。结果表明，提出的DOI编码方法对于需要高分辨率和高灵敏度的PET扫描仪和传统的采集系统是一种很有前途的候选方法。
Positron emission tomography (PET) detectors with the ability to encode depth-of-interaction (DOI) information allow us to simultaneously improve the spatial resolution and sensitivity of PET scanners. In this study, we propose a DOI PET detector based on a stair-pattern reflector arrangement inserted between pixelated crystals and a single-ended scintillation light readout. The main advantage of the proposed method is its simplicity; DOI information is decoded from a flood map and the data can be simply acquired by using a single-ended readout system. Another potential advantage is that the two-step DOI detectors can provide the largest peak position distance in a flood map because two-dimensional peak positions can be evenly distributed. We conducted a Monte Carlo simulation and obtained flood maps. Then, we conducted experimental studies using two-step DOI arrays of 5 x 5 Lu1.9Y0.1SiO5: Ce crystals with a cross-section of 1.7 x 1.7 mm(2) and different detector configurations: an unpolished single-layer (US) array, a polished single-layer (PS) array and a polished stacked two-layer (PT) array. For each detector configuration, both air gaps and room-temperature vulcanization (RTV) silicone gaps were tested. Detectors US and PT showed good peak separation in each scintillator with an average peak-to-valley ratio (PVR) and distance-to-width ratio (DWR) of 2.09 and 1.53, respectively. Detector PSRTV showed lower PVR and DWR (1.65 and 1.34, respectively). The configuration of detector PTAir is preferable for the construction of time-of-flight-DOI detectors because timing resolution was degraded by only about 40 ps compared with that of a non-DOI detector. The performance of detectors USAir and PSRTV was lower than that of a non-DOI detector, and thus these designs are favorable when the manufacturing cost is more important than timing performance. The results demonstrate that the proposed DOI-encoding method is a promising candidate for PET scanners that require high resolution and sensitivity and operate with conventional acquisition systems.