Radiation Oncology Department, Stanford University, Stanford, CA 94305, USA.
IEEE Trans Med Imaging. 2012 Aug;31(8):1620-7. doi: 10.1109/TMI.2012.2201165. Epub 2012 Jun 5.
This work provides a comprehensive Monte Carlo study of X-ray fluorescence computed tomography (XFCT) and K-edge imaging system, including the system design, the influence of various imaging components, the sensitivity and resolution under various conditions. We modified the widely used EGSnrc/DOSXYZnrc code to simulate XFCT images of two acrylic phantoms loaded with various concentrations of gold nanoparticles and Cisplatin for a number of XFCT geometries. In particular, reconstructed signal as a function of the width of the detector ring, its angular coverage and energy resolution were studied. We found that XFCT imaging sensitivity of the modeled systems consisting of a conventional X-ray tube and a full 2-cm-wide energy-resolving detector ring was 0.061% and 0.042% for gold nanoparticles and Cisplatin, respectively, for a dose of ∼ 10 cGy. Contrast-to-noise ratio (CNR) of XFCT images of the simulated acrylic phantoms was higher than that of transmission K-edge images for contrast concentrations below 0.4%.
这项工作提供了一个全面的蒙特卡罗研究 X 射线荧光计算机断层扫描（XFCT）和 K 边成像系统，包括系统设计、各种成像组件的影响、在各种条件下的灵敏度和分辨率。我们修改了广泛使用的 EGSnrc/DOSXYZnrc 代码，以模拟两个装有各种浓度金纳米粒子和顺铂的亚克力体模的 XFCT 图像，用于许多 XFCT 几何形状。特别是，研究了探测器环的宽度、其角覆盖范围和能量分辨率作为重建信号的函数。我们发现，由常规 X 射线管和全 2 厘米宽的能量分辨探测器环组成的模型系统的 XFCT 成像灵敏度分别为 0.061%和 0.042%，用于剂量约为 10 cGy 的金纳米粒子和顺铂。模拟亚克力体模的 XFCT 图像的对比噪声比（CNR）高于透射 K 边图像的 CNR，对于对比度浓度低于 0.4%的情况。
