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 demonstrated excellent accuracy in elemental material quantification. For example, relative root-mean-square errors of 4.5% for calcium and 5.2% for iodine were 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.

中文翻译：

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双能量差相对比度CT（DE-DPC-CT）成像。

当在给定对象中存在两种以上的元素材料时，当采用当前双能CT成像中的常规两种材料分解方案时，材料定量可能不够鲁棒和准确。在这项工作中，我们提出了一种创新的方案，可通过双能量差分相差CT（DE-DPC-CT）采集的测量结果完成精确的三材料分解。使用光栅干涉仪和具有两个能量仓的光子计数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实部，以实现三材料分解。使用DE-DPC-CT系统构建并测量了具有21个材料插件的物理模型。结果表明，元素材料定量分析具有出色的准确性。例如，使用建议的三材料分解方案，钙的相对均方根误差为4.5％，碘的相对均方根误差为5.2％。具有碘插入物的生物组织被用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，该方法能够正确地区分生物样本中的骨组织，碘和软组织。还执行了三光谱CT扫描以对DE-DPC-CT扫描的性能进行基准测试。结果表明，与三光谱CT扫描相比，DE-DPC-CT的材料分解具有更低的量化噪声。使用建议的三材料分解方案，钙的含量为5％，碘的含量为5.2％。具有碘插入物的生物组织被用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，该方法能够正确地区分生物样本中的骨组织，碘和软组织。还执行了三光谱CT扫描，以对DE-DPC-CT扫描的性能进行基准测试。结果表明，与三光谱CT扫描相比，DE-DPC-CT的材料分解具有更低的量化噪声。使用建议的三材料分解方案，钙的含量为5％，碘的含量为5.2％。具有碘插入物的生物组织用于证明所提出的光谱CT成像方法的潜在实用性。实验结果表明，该方法能够正确地区分生物样本中的骨组织，碘和软组织。还执行了三光谱CT扫描以对DE-DPC-CT扫描的性能进行基准测试。结果表明，与三光谱CT扫描相比，DE-DPC-CT的材料分解具有更低的量化噪声。实验结果表明，该方法能够正确地区分生物样本中的骨组织，碘和软组织。还执行了三光谱CT扫描以对DE-DPC-CT扫描的性能进行基准测试。结果表明，与三光谱CT扫描相比，DE-DPC-CT的材料分解具有更低的量化噪声。实验结果表明，该方法能够正确地区分生物样本中的骨组织，碘和软组织。还执行了三光谱CT扫描，以对DE-DPC-CT扫描的性能进行基准测试。结果表明，与三光谱CT扫描相比，DE-DPC-CT的材料分解具有更低的量化噪声。