Krenkel Martin, Toepperwien Mareike, Alves Frauke, Salditt Tim
Institut für Röntgenphysik, Georg-August-University Göttingen, Germany.
Max-Planck-Institute for Experimental Medicine and University Medical Center Göttingen, Germany.
Acta Crystallogr A Found Adv. 2017 Jul 1;73(Pt 4):282-292. doi: 10.1107/S2053273317007902. Epub 2017 Jun 29.
X-ray tomography at the level of single biological cells is possible in a low-dose regime, based on full-field holographic recordings, with phase contrast originating from free-space wave propagation. Building upon recent progress in cellular imaging based on the illumination by quasi-point sources provided by X-ray waveguides, here this approach is extended in several ways. First, the phase-retrieval algorithms are extended by an optimized deterministic inversion, based on a multi-distance recording. Second, different advanced forms of iterative phase retrieval are used, operational for single-distance and multi-distance recordings. Results are compared for several different preparations of macrophage cells, for different staining and labelling. As a result, it is shown that phase retrieval is no longer a bottleneck for holographic imaging of cells, and how advanced schemes can be implemented to cope also with high noise and inconsistencies in the data.
基于全场全息记录，利用自由空间波传播产生的相位对比，在低剂量条件下对单个生物细胞进行X射线断层扫描是可行的。基于X射线波导提供的准点源照明在细胞成像方面的最新进展，本文从几个方面扩展了这种方法。首先，基于多距离记录，通过优化的确定性反演扩展相位恢复算法。其次，使用不同的高级迭代相位恢复形式，用于单距离和多距离记录。对几种不同制备的巨噬细胞、不同的染色和标记的结果进行了比较。结果表明，相位恢复不再是细胞全息成像的瓶颈，以及如何实施先进方案来处理数据中的高噪声和不一致性。
