As the γ-ray energy increases, a reconstructed image becomes noisy and blurred due to the penetration of the γ-ray through the coded mask. Therefore, the thickness of the coded mask was increased for high energy regions, resulting in severely decreased the performance of the detection efficiency due to self-collimation by the mask. In order to overcome the limitation, a modified uniformly redundant array γ-ray imaging system using dual anti-mask method was developed, and its performance was compared and evaluated in high-energy radiation region. In the dual anti-mask method, the two shadow images, including the subtraction of background events, can simultaneously contribute to the reconstructed image. Moreover, the reconstructed images using each shadow image were integrated using a hybrid update maximum likelihood expectation maximization (h-MLEM). Using the quantitative evaluation method, the performance of the dual anti-mask method was compared with the previously developed collimation methods. As the shadow image which was subtracted the background events leads to a higher-quality reconstructed image, the reconstructed image of the dual anti-mask method showed high performance among the three collimation methods. Finally, the quantitative evaluation method proves that the performance of the dual anti-mask method was better than that of the previously reconstruction methods.

随着 γ 射线能量的增加，由于 γ 射线穿透编码掩模，重建的图像变得嘈杂和模糊。因此，对于高能量区域，编码掩模的厚度增加，导致由于掩模的自准直而严重降低检测效率的性能。为克服这一局限性，研制了一种改进的采用双反掩膜法的均匀冗余阵列γ射线成像系统，并对其在高能辐射区的性能进行了比较和评价。在双重反掩码方法中，两个阴影图像，包括背景事件的减法，可以同时对重建图像做出贡献。而且，使用混合更新最大似然期望最大化 (h-MLEM) 对使用每个阴影图像的重建图像进行集成。使用定量评估方法，将双重防掩蔽方法的性能与先前开发的准直方法进行了比较。由于减去背景事件的阴影图像导致了更高质量的重建图像，因此双抗掩蔽方法的重建图像在三种准直方法中表现出较高的性能。最后，定量评估方法证明双抗掩蔽方法的性能优于以前的重建方法。由于减去背景事件的阴影图像导致了更高质量的重建图像，因此双抗掩蔽方法的重建图像在三种准直方法中表现出较高的性能。最后，定量评估方法证明双抗掩蔽方法的性能优于以前的重建方法。由于减去背景事件的阴影图像导致了更高质量的重建图像，因此双抗掩蔽方法的重建图像在三种准直方法中表现出较高的性能。最后，定量评估方法证明双抗掩蔽方法的性能优于以前的重建方法。