论文标题
能量选择性X射线成像中的维度和背景取消
Dimensionality and Background Cancellation in Energy Selective X-Ray Imaging
论文作者
论文摘要
目的：通常认为属于人体材料的线性衰减系数在临床X射线能量范围内被两个基础函数跨越，尽管有证据表明该集合的维度大于两个。目前尚不清楚使用第三基函数在没有对比剂的情况下可能是有益的。 方法：在这项工作中，研究了基础分解方法中使用的基本函数数量的选择，以生成图像的任务，在该图像中，第三种材料与其他两种材料的背景分开，在这种情况下，没有任何材料在考虑到X射线范围内的K边缘（20-140 KEV）。用模拟的幻影研究了将铁与肝脏和脂肪组织混合物分离的情况，该模拟幻影结合了随机和逼真的组织变异性。 结果：将第三基函数的包含在产生图像中的均方误差方面提高了铁浓度的定量估计值。 结论：在基础分解中包含第三基础功能对于研究成像任务至关重要，并且可能具有潜在的应用，以定量估计来自材料分解图像的铁浓度。
Purpose: The set of linear attenuation coefficients that belong to materials in the human body is commonly assumed to be spanned by two basis functions in the range of clinical x-ray energies, even though there is evidence that the dimensionality of this set is greater than two. It has not yet been clear that the use of a third basis function could be beneficial in absence of contrast agents. Approach: In this work, the choice of the number of basis functions used in the basis decomposition method is studied for the task of producing an image where a third material is separated from a background of two other materials, in a case where none of the materials have a K-edge in the range of considered x-ray energies (20-140 keV). The case of separating iron from mixtures of liver and adipose tissue is studied with a simulated phantom which incorporates random and realistic tissue variability. Results: Inclusion of a third basis function improves the quantitative estimate of iron concentration by several orders of magnitude in terms of mean squared error in the resulting image. Conclusions: The inclusion of a third basis function in the basis decomposition is essential for the studied imaging task and could have potential application for quantitative estimation of iron concentration from material decomposed images.
