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Abstract：
Following the rapid, but independent, diffusion of x-ray spectral and phase-contrast systems, this work demonstrates the first combination of spectral and phase-contrast computed tomography (CT) obtained by using the edge-illumination technique and a CdTe small-pixel (62μm) spectral detector. A theoretical model is introduced, starting from a standard attenuation-based spectral decomposition and leading to spectral phase-contrast material decomposition. Each step of the model is followed by quantification of accuracy and sensitivity on experimental data of a test phantom containing different solutions with known concentrations. An example of a micro CT application (20μm voxel size) on an iodine-perfusedex vivomurine model is reported. The work demonstrates that spectral-phase contrast combines the advantages of spectral imaging, i.e. high-Zmaterial discrimination capability, and phase-contrast imaging, i.e. soft tissue sensitivity, yielding simultaneously mass density maps of water, calcium, and iodine with an accuracy of 1.1%, 3.5%, and 1.9% (root mean square errors), respectively. Results also show a 9-fold increase in the signal-to-noise ratio of the water channel when compared to standard spectral decomposition. The application to the murine model revealed the potential of the technique in the simultaneous 3D visualization of soft tissue, bone, and vasculature. While being implemented by using a broad spectrum (pink beam) at a synchrotron radiation facility (Elettra, Trieste, Italy), the proposed experimental setup can be readily translated to compact laboratory systems including conventional x-ray tubes.
摘要：
跟随快速，但独立，X射线光谱和相衬系统的扩散，这项工作展示了通过使用边缘照明技术和CdTe小像素（62μm）光谱探测器获得的光谱和相衬计算机断层扫描（CT）的第一个组合。介绍了一种理论模型,从基于标准衰减的光谱分解开始，并导致光谱相衬材料分解。在模型的每个步骤之后，都要对包含已知浓度的不同溶液的测试体模的实验数据进行准确性和灵敏度的量化。报道了在碘-perfusedex病毒蛋白模型上应用微CT（20μm体素大小）的示例。这项工作表明，光谱相衬结合了光谱成像的优点，即高Z材料辨别能力，和相衬成像，即软组织敏感性，同时产生水的质量密度图，钙，碘的准确度为1.1%，3.5%,和1.9%(均方根误差)，分别。结果还显示，与标准频谱分解相比，水通道的信噪比增加了9倍。在鼠模型中的应用揭示了该技术在软组织同时3D可视化中的潜力，骨头,和脉管系统。在同步加速器辐射设施（Elettra，的里雅斯特,意大利),所提出的实验装置可以很容易地转换成紧凑的实验室系统，包括传统的X射线管。
