Increased separability of K-edge nanoparticles by photon-counting detectors for spectral micro-CT
Increased separability of K-edge nanoparticles by photon-counting detectors for spectral micro-CT
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DOI：
10.3233/xst-18382
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发表时间：
2018-01-01
影响因子：
3
通讯作者：
Wang, Ge
中科院分区：
文献类型：
--
作者：
Getzin, Matthew;Garfield, Josephine J.;Wang, Ge
背景：采用光子计数探测器（PCD）和高 Z 材料的 X 射线 CT/微型 CT 方法是一个热门研究课题。一种使用 PCD 的方法允许在 5 个能量窗口中进行光谱成像，而传统的 X 射线探测器仅收集能量积分数据。 目的：证明使用 PCD、多元分析和线性判别方法增强对比材料的分离。 方法：在 MARS 光谱微型 CT 上扫描含有碘和水性纳米材料的体模。图像体积被分割成单独的特定材料群体。通过计算单变量、伪传统和多变量能谱 CT 数据集中的 T-2 检验统计量进行对比比较。还评估了 Fisher 判别分析 (FDA) 后的可分离性。结果：由于光谱扩展，为材料比较计算的 T-2 值有所增加。大多数测试的造影剂显示 T-2 值增加了大约 2 - 3 倍。纯和混合镧系元素图像集中的总显着 T-2 统计数据在光谱数据集中增加。 FDA 模型用于将数据维度缩减为 3D，从而很好地转换为通用色彩空间以增强图像可视化。结论：这项工作巩固了使用微 CT 进行基于光子计数的材料分解的基础工作，促进了新型纳米材料及其临床前应用的未来发展。
BACKGROUND: X-ray CT/micro-CT methods with photon-counting detectors (PCDs) and high Z materials are a hot research topic. One method using PCDs allows for spectral imaging in 5 energy windows while conventional X-ray detectors only collect energy-integrating data.OBJECTIVE: To demonstrate the enhanced separation of contrast materials by using PCDs, multivariate analysis, and linear discriminant methods.METHODS: Phantoms containing iodine and aqueous nanomaterials were scanned on a MARS spectral micro-CT. Image volumes were segmented into separate material-specific populations. Contrast comparisons were made by calculating T-2 test statistics in the univariate, pseudo-conventional and multivariate, spectral CT data sets. Separability after Fisher discriminant analysis (FDA) was also assessed.RESULTS: The T-2 values calculated for material comparisons increased as a result of the spectral expansion. The majority of the tested contrast agents showed increased T-2 values by a factor of similar to 2 - 3. The total significant T-2 statistics in the pure and mixed lanthanide image sets increased in the spectral data set. FDA models are used for data dimension reduction into 3D which is nicely translated to common color spaces for enhanced image visualization.CONCLUSION: This work consolidates the groundwork for photon-counting-based material decomposition with micro-CT, facilitating future development of novel nanomaterials and their preclinical applications.