In the inline phase contrast x-ray tomography the reconstructed apparent linear attenuation coefficient values may be greatly larger than sample's linear attenuation coefficients or even be negative. In this work we present a general formula to quantitatively relate the apparent linear attenuation coefficient values in cone-beam phase contrast tomography to sample's linear attenuation coefficients and refractive indices. This formula overcomes the gross inaccuracy of the existing formula in the literature in analyzing high-resolution phase contrast tomography, and it will be useful for correctly interpreting and quantifying the apparent linear attenuation coefficients in cone-beam x-ray phase contrast tomography.

中文翻译：

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相衬 X 射线断层扫描中的表观线性衰减系数。

在在线相衬 X 射线断层扫描中，重建的表观线性衰减系数值可能远大于样本的线性衰减系数值，甚至为负值。在这项工作中，我们提出了一个通用公式，将锥形束相衬断层扫描中的表观线性衰减系数值与样品的线性衰减系数和折射率定量相关。该公式克服了文献中现有公式在分析高分辨率相衬断层扫描时存在的严重不准确的问题，有助于正确解释和量化锥形束X射线相衬断层扫描中的表观线性衰减系数。