Sung Yongjin, Nelson Brandon, Shanblatt Elisabeth R, Gupta Rajiv, McCollough Cynthia H, Graves William S
College of Engineering & Applied Science, University of Wisconsin-Milwaukee, 3200 North Cramer Street, Milwaukee, WI, 53211, USA.
Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
Med Phys. 2020 Nov;47(11):5761-5771. doi: 10.1002/mp.14479. Epub 2020 Oct 7.
Demonstrate realistic simulation of grating-based x-ray phase-contrast imaging (GB-XPCI) using wave optics and the four-dimensional Mouse Whole Body (MOBY) phantom defined with non-uniform rational B-splines (NURBS).
We use a full-wave approach, which uses wave optics for x-ray wave propagation from the source to the detector. This forward imaging model can be directly applied to NURBS-defined numerical phantoms such as MOBY. We assign the material properties (attenuation coefficient and electron density) of each model part using the data for adult human tissues. The Poisson noise is added to the simulated images based on the calculated photon flux at each pixel.
We simulate the intensity images of the MOBY phantom for eight different grating positions. From the simulated images, we calculate the absorption, differential phase, and normalized visibility contrast images. We also predict how the image quality is affected by different exposure times.
GB-XPCI can be simulated with the full-wave approach and a realistic numerical phantom defined with NURBS.
利用波动光学和用非均匀有理B样条(NURBS)定义的四维小鼠全身(MOBY)体模,演示基于光栅的X射线相衬成像(GB-XPCI)的真实模拟。
我们采用全波方法,该方法利用波动光学来模拟X射线从源到探测器的传播。这种正向成像模型可以直接应用于如MOBY这样由NURBS定义的数值体模。我们使用成人组织的数据为每个模型部分指定材料属性(衰减系数和电子密度)。基于每个像素处计算出的光子通量,将泊松噪声添加到模拟图像中。
我们模拟了MOBY体模在八个不同光栅位置的强度图像。从模拟图像中,我们计算出吸收、微分相位和归一化可见度对比度图像。我们还预测了不同曝光时间对图像质量的影响。
GB-XPCI可以用全波方法和由NURBS定义的真实数值体模进行模拟。