TY - JOUR A1 - Homberg, U. A1 - Baum, D. A1 - Prohaska, S. A1 - Günster, Jens A1 - Krauss-Schüler, Stefanie T1 - Adapting trabecular structures for 3D printing: an image processing approach based on μCT data N2 - Materials with a trabecular structure notably Combine advantages such as lightweight, reasonable strength, and permeability for fl uids. This combination of advantages is especially interesting for tissue engineering in trauma surgery and orthopedics. Bone-substituting scaffolds for instance are designed with a trabecular structure in order to allow cell migration for bone ingrowth and vascularization. An emerging and recently very popular technology to produce such complex, porous structures is 3D printing. However, several technological aspects regarding the scaffold architecture, the printable resolution, and the feature size have to be considered when fabricating scaffolds for bone tissue replacement and regeneration. Here, we present a strategy to assess and prepare realistic trabecular structures for 3D printing using image analysis with the aim of preserving the structural elements. We discuss critical conditions of the printing system and present a 3-stage approach to adapt a trabecular structure from μ CT data while incorporating knowledge about the printing system. In the first stage, an image-based extraction of solid and void structures is performed, which results in voxel- and graph-based representations of the extracted structures. These representations not only allow us to quantify geometrical properties such as pore size or strut geometry and length. But, since the graph represents the geometry and the topology of the initial structure, it can be used in the second stage to modify and adjust feature size, volume and sample size in an easy and consistent way. In the final reconstruction stage, the graph is then converted into a voxel representation preserving the topology of the initial structure. This stage generates a model with respect to the printing conditions to ensure a stable and controlled voxel placement during the printing process. KW - Additive manufacturing, 3D printing KW - Trabecular structures KW - Image-based analysis PY - 2017 DO - https://doi.org/10.1088/2057-1976/aa7611 SN - 2057-1976 VL - 3 IS - 3 SP - Article 035027, 1 EP - 14 PB - IOP Publishing Ltd AN - OPUS4-40744 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Ritter, Z. A1 - Staude, Andreas A1 - Prohaska, S. A1 - Felsenberg, D. ED - Naik, G. R. T1 - Osteocytes characterization using synchrotron radiation CT and finite element analysis N2 - Since a correlation between osteocyte number and their morphology with bone aging or its response to pharmacological treatment appears to exist, a methodology to characterize osteocytes from bone biopsies becomes important. In this chapter, the usage of synchrotron measurements, algorithms for image analysis (Amira, ZIB), and the finite element method using parallelized computational resources for topological analysis of osteocytes is explained and discussed. Different routines normally applied for material characterization of network-like structures (skeletonization) have been adapted to visualize osteocytes along bone cement lines at high resolution (2.174 µm). The different steps concerning to counting osteocytes and analyzing the mechanical behavior of bones are illustrated with an example. Our findings showed a clear alignment of the osteocytes along the cement lines. Interestingly, at the regions near the bone surface with reduced mineralization grade, osteocytes were mainly aligned along the close to high mineralized region. Apparently, not only osteocytes number is reduced with aging but their size increases and they become sparely distributed in comparison with the healthy bone samples from the human mandible. Automatic tetrahedron mesh generation using the "tetragen" tool from Amira worked adequately for meshing the biopsies with a resolution of 20 µm, but meshing biopsies with osteocytes embedded on the bone matrix from the SR-CT samples consumes an enormous amount of time, due to necessary adjustments for avoiding intersections and conserving model closeness. KW - CT KW - Finite element analysis KW - Osteocytes characterization KW - Synchrotron radiation PY - 2012 SN - 978-953-51-0412-4 DO - https://doi.org/10.5772/35242 SP - 165 EP - 190 PB - InTech CY - Rijeka AN - OPUS4-25845 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -