Dahmen Tim, Baudoin Jean-Pierre, Lupini Andrew R, Kübel Christian, Slusallek Philipp, de Jonge Niels
1 German Research Center for Artificial Intelligence GmbH (DFKI), 66123 Saarbrücken, Germany.
2 Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232-0615, USA.
Microsc Microanal. 2014 Apr;20(2):548-60. doi: 10.1017/S1431927614000075. Epub 2014 Feb 19.
In this study, a combined tilt- and focal series is proposed as a new recording scheme for high-angle annular dark-field scanning transmission electron microscopy (STEM) tomography. Three-dimensional (3D) data were acquired by mechanically tilting the specimen, and recording a through-focal series at each tilt direction. The sample was a whole-mount macrophage cell with embedded gold nanoparticles. The tilt-focal algebraic reconstruction technique (TF-ART) is introduced as a new algorithm to reconstruct tomograms from such combined tilt- and focal series. The feasibility of TF-ART was demonstrated by 3D reconstruction of the experimental 3D data. The results were compared with a conventional STEM tilt series of a similar sample. The combined tilt- and focal series led to smaller "missing wedge" artifacts, and a higher axial resolution than obtained for the STEM tilt series, thus improving on one of the main issues of tilt series-based electron tomography.
在本研究中，提出了一种倾斜和聚焦系列相结合的方法，作为高角度环形暗场扫描透射电子显微镜（STEM）断层扫描的一种新记录方案。通过机械倾斜样品并在每个倾斜方向记录一个焦深系列来获取三维（3D）数据。样品是一个嵌入了金纳米颗粒的巨噬细胞整装标本。引入了倾斜-聚焦代数重建技术（TF-ART）作为一种从这种倾斜和聚焦系列相结合的数据中重建断层图像的新算法。通过对实验3D数据进行三维重建证明了TF-ART的可行性。将结果与类似样品的传统STEM倾斜系列进行了比较。倾斜和聚焦系列相结合导致“缺失楔形”伪影更小，并且轴向分辨率高于STEM倾斜系列，从而改善了基于倾斜系列的电子断层扫描的一个主要问题。
