Tashima Hideaki, Yoshida Eiji, Hirano Yoshiyuki, Nishikido Fumihiko, Inadama Naoko, Murayama Hideo, Yamaya Taiga
Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba, 263-8555, Japan,
Radiol Phys Technol. 2014 Jul;7(2):379-86. doi: 10.1007/s12194-014-0276-z. Epub 2014 Jun 18.
In the development of depth-of-interaction (DOI)-positron emission tomography (PET) detectors, one of the important steps toward their practical use is an evaluation of their imaging performance, such as the spatial resolution as measured by use of a point source and a one-pair experimental system which simulates actual PET geometries. The DOI-PET detectors have a broad field of view providing good imaging performance compared with conventional detectors. Therefore, evaluation including the region from the center to the periphery close to the detector ring is required in an effort to show their advanced performance regarding uniform spatial resolution. In this study, we aimed to develop and evaluate an efficient one-pair experimental system for demonstration of the DOI-PET detector performance. For this purpose, we propose a one-pair experimental system that can simulate an arbitrary ring diameter and acquire projection data efficiently by skipping unnecessary combinations according to the position of the point source. As a result, the proposed system and our measuring scheme could significantly reduce the total measurement time, especially for a large ring size such as that used in brain PET scanners and whole-body PET scanners. We used the system to evaluate the X'tal cube PET detector with a 2-mm cubic crystal array arranged in simulated PET geometries with ring diameters of 8.2 and 14.6 cm for 12 and 18 detector blocks, respectively. The results showed that a uniform spatial resolution was achieved even in the peripheral region, and measurements were obtained semi-automatically in a short time.
在深度交互（DOI）正电子发射断层扫描（PET）探测器的开发过程中，朝着其实际应用迈出的重要步骤之一是评估其成像性能，例如通过使用点源和模拟实际PET几何形状的单对实验系统测量的空间分辨率。与传统探测器相比，DOI-PET探测器具有广阔的视野，成像性能良好。因此，为了展示其在均匀空间分辨率方面的先进性能，需要对从探测器环中心到周边的区域进行评估。在本研究中，我们旨在开发并评估一种用于展示DOI-PET探测器性能的高效单对实验系统。为此，我们提出了一种单对实验系统，该系统可以模拟任意环直径，并根据点源的位置跳过不必要的组合，从而高效地获取投影数据。结果表明，所提出的系统和我们的测量方案可以显著减少总测量时间，特别是对于大脑PET扫描仪和全身PET扫描仪中使用的大尺寸环。我们使用该系统在模拟PET几何形状中评估了具有2毫米立方晶体阵列的X'tal cube PET探测器，环直径分别为8.2厘米和14.6厘米，分别用于12个和18个探测器模块。结果表明，即使在周边区域也能实现均匀的空间分辨率，并且在短时间内半自动获得了测量结果。
