Yang Xiaogang, Kahnt Maik, Brückner Dennis, Schropp Andreas, Fam Yakub, Becher Johannes, Grunwaldt Jan Dierk, Sheppard Thomas L, Schroer Christian G
FS-PETRA, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, D-22607 Hamburg, Germany.
Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, Engesserstraße 20, 76131 Karlsruhe, Germany.
J Synchrotron Radiat. 2020 Mar 1;27(Pt 2):486-493. doi: 10.1107/S1600577520000831. Epub 2020 Feb 18.
This paper presents a deep learning algorithm for tomographic reconstruction (GANrec). The algorithm uses a generative adversarial network (GAN) to solve the inverse of the Radon transform directly. It works for independent sinograms without additional training steps. The GAN has been developed to fit the input sinogram with the model sinogram generated from the predicted reconstruction. Good quality reconstructions can be obtained during the minimization of the fitting errors. The reconstruction is a self-training procedure based on the physics model, instead of on training data. The algorithm showed significant improvements in the reconstruction accuracy, especially for missing-wedge tomography acquired at less than 180° rotational range. It was also validated by reconstructing a missing-wedge X-ray ptychographic tomography (PXCT) data set of a macroporous zeolite particle, for which only 51 projections over 70° could be collected. The GANrec recovered the 3D pore structure with reasonable quality for further analysis. This reconstruction concept can work universally for most of the ill-posed inverse problems if the forward model is well defined, such as phase retrieval of in-line phase-contrast imaging.
本文提出了一种用于断层重建的深度学习算法(GANrec)。该算法使用生成对抗网络(GAN)直接求解拉东变换的逆问题。它适用于独立的正弦图,无需额外的训练步骤。已开发的GAN用于使输入正弦图与从预测重建生成的模型正弦图相匹配。在拟合误差最小化过程中可以获得高质量的重建结果。重建是基于物理模型而非训练数据的自训练过程。该算法在重建精度方面有显著提高,特别是对于在小于180°旋转范围内采集的缺楔断层扫描。通过重建大孔沸石颗粒的缺楔X射线叠层断层扫描(PXCT)数据集对其进行了验证,对于该数据集,在70°范围内仅能收集到51个投影。GANrec以合理的质量恢复了三维孔隙结构以供进一步分析。如果正向模型定义良好,这种重建概念可以普遍适用于大多数不适定的逆问题,例如在线相衬成像的相位恢复。