X-ray phase contrast imaging (PCI) combined with phase retrieval has the potential to improve soft-material visibility and discrimination. This work examined the accuracy, image quality gains, and robustness of a spectral phase retrieval method proposed by our group. Spectroscopic PCI measurements of a physical phantom were obtained using state-of-the-art photon-counting detectors in combination with a polychromatic x-ray source. The phantom consisted of four poorly attenuating materials. Excellent accuracy was demonstrated in simultaneously retrieving the complete refractive properties (photoelectric absorption, attenuation, and phase) of these materials. Approximately 10 times higher SNR was achieved in retrieved images compared to the original PCI intensity image. These gains are also shown to be robust against increasing quantum noise, even for acquisition times as low as 1 s with a low-flux microfocus x-ray tube (average counts of 250 photons/pixels). We expect that this spectral phase retrieval method, adaptable to several PCI geometries, will allow significant dose reduction and improved material discrimination in clinical and industrial x-ray imaging applications.

中文翻译：

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使用能量分辨量子检测器进行低光子计数的定量相位检索

X 射线相位对比成像 (PCI) 与相位检索相结合有可能提高软材料的可见性和辨别力。这项工作检查了我们小组提出的光谱相位检索方法的准确性、图像质量增益和稳健性。物理体模的光谱 PCI 测量是使用最先进的光子计数检测器结合多色 X 射线源获得的。幻影由四种衰减不佳的材料组成。在同时检索这些材料的完整折射特性（光电吸收、衰减和相位）时，展示了出色的准确性。与原始 PCI 强度图像相比，检索图像的 SNR 提高了大约 10 倍。这些增益也显示出对增加的量子噪声具有鲁棒性，即使采集时间低至 1 秒，使用低通量微焦点 X 射线管（平均计数 250 个光子/像素）。我们期望这种适用于多种 PCI 几何形状的光谱相位检索方法将在临床和工业 X 射线成像应用中显着减少剂量并改进材料辨别力。