Title: Moire Artifact Reduction in Grating Interferometry Using Multiple Harmonics and Total Variation Regularization Show Chinese title

Title: 基于多谐波和总变分正则化的光栅干涉仪莫尔伪影减少

Abstract: X-ray interferometry is an emerging imaging modality with a wide range of potential clinical applications, including lung and breast imaging, as well as non destructive testing in fields such as additive manufacturing and porosimetry. A grating interferometer uses a diffraction grating to produce a periodic interference pattern and measures how a patient or sample perturbs the pattern, producing three unique images that highlight X-ray absorption, refraction, and small angle scattering, known as the attenuation, differential phase, and dark-field images. Image artifacts unique to X-ray interferometry are introduced when assuming the fringe pattern is perfectly sinusoidal and the phase steps are evenly spaced. Inaccuracies in grating position, coupled with multi-harmonic fringes, lead to Moire artifacts. We have developed an image recovery algorithm that estimates the true phase stepping positions using multiple harmonics and total variation regularization, removing the Moire artifacts present in the attenuation, differential phase, and dark-field images. We demonstrate the algorithm's utility for the Talbot-Lau and Modulated Phase Grating interferometers by imaging multiple samples, including PMMA microspheres and a euthanized mouse. Show Chinese abstract

Abstract: X射线干涉测量是一种新兴的成像方式，具有广泛的潜在临床应用，包括肺部和乳腺成像，以及在增材制造和孔隙度分析等领域中的无损检测。 光栅干涉仪使用衍射光栅产生周期性干涉图案，并测量患者或样品如何扰动该图案，生成三种独特的图像，突出显示X射线吸收、折射和小角度散射，称为衰减图像、差分相位图像和暗场图像。 当假设条纹图案是完美正弦波且相位步长均匀分布时，会引入X射线干涉测量特有的图像伪影。 光栅位置的不准确与多谐波条纹会导致莫尔伪影。 我们开发了一种图像恢复算法，利用多个谐波和总变分正则化来估计真实的相位步进位置，消除了衰减图像、差分相位图像和暗场图像中存在的莫尔伪影。 我们通过成像多个样品，包括PMMA微球和安乐死的小鼠，展示了该算法在Talbot-Lau和调制相位光栅干涉仪中的实用性。