Dual Energy Differential Phase Contrast CT (DE-DPC-CT) Imaging.
Dual Energy Differential Phase Contrast CT (DE-DPC-CT) Imaging.
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DOI：
10.1109/tmi.2020.2990347
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发表时间：
2020-11
影响因子：
10.6
通讯作者：
Chen GH
中科院分区：
文献类型：
--
作者：
Ji X;Zhang R;Li K;Chen GH
当在给定对象中存在多于两种元素材料时，当采用当前双能量CT成像中的常规双材料分解方案时，材料量化可能不是鲁棒的和准确的。在这项工作中，我们提出了一个创新的方案，以完成准确的三种材料分解与测量从双能量微分相衬CT（DE-DPC-CT）采集。利用光栅干涉仪和双能箱光子计数CT成像系统构建了DE-DPC-CT系统。DE-DPC-CT系统可以同时测量复折射率的虚部和真实的部，以实现三种材料的分解。用DE-DPC-CT系统构建了21种材料插入物的物理体模并进行了测量。结果证明了元素材料定量的优异准确性。例如，钙和碘的相对均方根误差分别为4.5%和5.2%，已经实现了使用所提出的三种材料的分解方案。使用带有碘插入物的生物组织来证明所提出的光谱CT成像方法的潜在实用性。实验结果表明，该方法能够正确区分生物标本样本中的骨结构、碘和软组织。还进行了三光谱CT扫描，以确定DE-DPC-CT扫描的性能。结果表明，从DE-DPC-CT的材料分解有一个更低的量化噪声比从三谱CT扫描。
When more than two elemental materials are present in a given object, material quantification may not be robust and accurate when the routine two-material decomposition scheme in current dual energy CT imaging is employed. In this work, we present an innovative scheme to accomplish accurate three-material decomposition with measurements from a dual energy differential phase contrast CT (DE-DPC-CT) acquisition. A DE-DPC-CT system was constructed using a grating interferometer and a photon counting CT imaging system with two energy bins. The DE-DPC-CT system can simultaneously measure both the imaginary and the real part of the complex refractive index to enable a three-material decomposition. Physical phantom with 21 material inserts were constructed and measured using DE-DPC-CT system. Results demonstrates excellent accuracy in elemental material quantification. For example, relative root-mean-square errors of 4.5% for calcium and 5.2% for iodine have been achieved using the proposed three-material decomposition scheme. Biological tissues with iodine inserts were used to demonstrate the potential utility of the proposed spectral CT imaging method. Experimental results showed that the proposed method correctly differentiates the bony structure, iodine, and the soft tissue in the biological specimen samples. A triple spectra CT scan was also performed to benchmark the performance of the DE-DPC-CT scan. Results demonstrated that the material decomposition from the DE-DPC-CT has a much lower quantification noise than that from the triple spectra CT scan.