Development of crosshair light sharing PET detector with TOF and DOI capabilities using fast LGSO scintillator
Development of crosshair light sharing PET detector with TOF and DOI capabilities using fast LGSO scintillator
复制标题
使用快速 LGSO 闪烁体开发具有 TOF 和 DOI 功能的十字线光共享 PET 探测器
DOI：
10.1088/1361-6560/ac2f8b
复制
发表时间：
2021
影响因子：
3.5
通讯作者：
Yamaya Taiga
中科院分区：
文献类型：
--
作者：
Yoshida Eiji;Obata Fujino;Kamada Kei;Yoshikawa Akira;Yamaya Taiga
飞行时间（TOF）和相互作用深度（DOI）被公认为是改善PET图像质量的重要信息。由于这些信息类型不相关，许多TOF-DOI探测器已被开发，但只有少数报告的高分辨率探测器（如1.5毫米分辨率）的大脑PET系统。基于DOI检测器，它使单端读出通过光学耦合一对晶体，并具有一个回路结构，我们已经开发了十字准线光共享（CLS）PET检测器，光学耦合的四个回路结构，由四等分晶体的大小相当于一个光传感器，四个光传感器在紧密接近安排在风车形状。即使作为高分辨率探测器，CLS PET探测器也可以同时获得TOF和DOI信息。然而，CLS PET探测器的符合分辨时间（CRT）需要进一步改进，以应用于脑部PET系统。最近，开发了一种快速LGSO晶体，与GFAG晶体相比，它在探测效率和CRT方面具有优势。我们研制了用于TOF-DOI脑PET系统的快速LGSO晶体CLS PET探测器，晶体尺寸为1.45× 1.45× 15 mm 3，所有表面均经过化学刻蚀。该探测器由14× 14晶体阵列和8× 8 MPPC阵列组成，在511 keV能量下的能量分辨率为10.1%，在662 keV能量下的DOI分辨率为4.7 mm，CRT为293 ps，能量窗口为440-620 keV。与我们以前的CLS PET探测器相比，能量分辨率提高了30%，时间分辨率提高了32%。
ObjectiveTime-of-flight (TOF) and depth-of-interaction (DOI) are well recognized as important information to improve PET image quality. Since such information types are not correlated, many TOF-DOI detectors have been developed but there are only a few reports of high-resolution detectors (eg 1.5 mm resolution) for brain PET systems. Based on the DOI detector, which enables single-ended readout by optically coupling a pair of crystals and having a loop structure, we have developed the crosshair light sharing (CLS) PET detector that optically couples the four-loop structure, consisting of quadrisected crystals comparable in size to a photo-sensor, to four photo-sensors in close proximity arranged in a windmill shape. Even as a high-resolution detector, the CLS PET detector could obtain both TOF and DOI information. The coincidence resolving time (CRT) of the CLS PET detector needs to be further improved, however, for application to the brain PET system. Recently, a fast LGSO crystal was developed which has advantages in detection efficiency and CRT compared to the GFAG crystal. In this work, we developed the CLS PET detector using the fast LGSO crystal for the TOF-DOI brain PET system.ApproachThe crystals were each 1.45× 1.45× 15 mm 3 and all surfaces were chemically etched. The CLS PET detector consisted of a 14× 14 crystal array optically coupled to an 8× 8 MPPC array.Main resultsThe fast LGSO array provided 10.1% energy resolution at 511 keV, 4.7 mm DOI resolution at 662 keV, and 293 ps CRT with the energy window of 440–620 keV.SignificanceThe developed CLS PET detector has 290% higher coincidence sensitivity, 30% better energy resolution, and 32% better time resolution compared to our previous CLS PET detector.