Simulation studies of a new ‘OpenPET’ geometry based on a quad unit of detector rings
Simulation studies of a new ‘OpenPET’ geometry based on a quad unit of detector rings
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基于探测器环四单元的新型“OpenPET”几何结构的仿真研究
DOI：
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发表时间：
2009
影响因子：
3.5
通讯作者：
H. Murayama
中科院分区：
文献类型：
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作者：
T. Yamaya;T. Inaniwa;E. Yoshida;F. Nishikido;K. Shibuya;N. Inadama;H. Murayama
我们提出了一种‘OpenPET’几何结构，它由两个轴向长度为W的探测器环组成，每个环在轴向上由间隙G隔开。为了获得2W+G的轴向连续视场(FOV)，G的最大极限必须是W。然而，出现了两个灵敏度谷，在间隙的两边各一个。在实践中，为了补偿敏感度的下降，这个差值应该是G<；W。在本文中，我们提出了一种在保持间隙的同时提高灵敏度均匀性的替代方法。拟议的几何结构由四个探测器环单元组成，这些单元是通过将探测器环的每个右单元和左单元分为两个单元而获得的。内部两个单元形成主间隙，外部两个单元适当放置，以提高灵敏度的一致性。对几何形状进行了优化，使灵敏度分布的标准差最小。数值仿真结果支持了该方法的有效性。外部单元补偿了主间隙两侧的灵敏度谷。应该为所需的应用设计更合适的几何形状，例如长轴向FOV PET和在束式PET。
We have proposed an ‘OpenPET’ geometry which consists of two detector rings of axial length W each axially separated by a gap G. In order to obtain an axially continuous field-of-view (FOV) of 2W+G, the maximum limit for G must be W. However, two valleys of sensitivity appear, one on each side of the gap. In practice, the gap should be G<W in order to compensate for the sensitivity valleys. In this paper, we proposed an alternative method to improve uniformity of the sensitivity while maintaining the gap. The proposed geometry consisted of four units of detector rings obtained by dividing each right and left unit of detector rings into two units. The inner two units formed the main gap, and the outer two units were appropriately placed to improve the uniformity of sensitivity. The geometry was optimized to minimize the standard deviation of the sensitivity distribution. Numerical simulation results supported the effectiveness of the proposed method. The outer units compensated for the sensitivity valleys on both sides of the main gap. A more appropriate geometry should be designed for the desired application, such as a long axial FOV PET and in-beam PET.