Dual-energy computed tomography (CT) has a better material determination capability than traditional CT. In this article, we develop a dual-layer dual-energy micrometer CT (DEMCT) imaging system with micrometer spatial resolution. The detector of the DEMCT system uses cerium-doped gadolinium aluminum gallium garnet (GAGG:Ce) and cerium-doped lutetium yttrium oxyorthosilicate (LYSO:Ce) scintillators to absorb X-rays of different energies, which is a new application of GAGG:Ce scintillator. As GAGG:Ce and LYSO:Ce have high light yields and their emission wavelengths match well with the quantum efficiency of common charge-coupled device (CCD), thicknesses of the scintillators are allowed to be thin, which is of great significance for high-resolution imaging due to the limitation of the depth of field of objectives. We propose a mechanical adjustment method for registering high-energy and low-energy images, which saves the postprocessing time and avoids oscillating or nonconvergent iteration results of mathematical registration methods. Meanwhile, in order to increase the dual-energy spectra separation of materials detection in the DEMCT, a fast optimal kilovolt peak selection method is proposed. Results show that the DEMCT has the spatial resolution of $2~\mu \text{m}$ in low-energy imaging and $4~\mu \text{m}$ in high-energy imaging. In addition, materials of a silica mixture sample are clearly separated by the pixel selection of the energy map based on the DEMCT data. The proposed DEMCT system has the potential to separate materials that cannot be correctly determined on traditional CT.

中文翻译：

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使用GAGG：Ce和LYSO：Ce闪烁体的双能Micro-CT

双能计算机断层扫描（CT）具有比传统CT更好的材料确定能力。在本文中，我们开发了一种具有千分尺空间分辨率的双层双能千分尺CT（DEMCT）成像系统。DEMCT系统的检测器使用掺杂铈的aluminum铝镓石榴石（GAGG：Ce）和掺杂铈的氧化酸钇钇（LYSO：Ce）闪烁体来吸收不同能量的X射线，这是GAGG：Ce的新应用闪烁体。由于GAGG：Ce和LYSO：Ce的光产率很高，并且它们的发射波长与普通电荷耦合器件（CCD）的量子效率非常匹配，因此可以使闪烁体的厚度变薄，这对于由于物镜景深的限制，无法进行高分辨率成像。我们提出了一种用于调整高能和低能图像的机械调整方法，该方法可节省后处理时间，并且避免了数学配准方法的振荡或非收敛迭代结果。同时，为了增加DEMCT中材料检测的双能谱分离，提出了一种快速的最佳千伏峰选择方法。结果表明DEMCT的空间分辨率为 $ 2〜\ mu \ text {m} $ 在低能成像中 $ 4〜\ mu \ text {m} $ 在高能成像中。另外，通过基于DEMCT数据的能量图的像素选择，可以清楚地分离出二氧化硅混合物样品的材料。提议的DEMCT系统具有分离传统CT无法正确确定材料的潜力。