TY - JOUR A1 - Rigort, Alexander A1 - Günther, David A1 - Hegerl, Reiner A1 - Baum, Daniel A1 - Weber, Britta A1 - Prohaska, Steffen A1 - Medalia, Ohad A1 - Baumeister, Wolfgang A1 - Hege, Hans-Christian T1 - Automated segmentation of electron tomograms for a quantitative description of actin filament networks JF - Journal of Structural Biology Y1 - 2012 U6 - https://doi.org/10.1016/j.jsb.2011.08.012 VL - 177 SP - 135 EP - 144 ER - TY - CHAP A1 - Homberg, Ulrike A1 - Baum, Daniel A1 - Prohaska, Steffen A1 - Kalbe, Ute A1 - Witt, Karl Josef T1 - Automatic Extraction and Analysis of Realistic Pore Structures from µCT Data for Pore Space Characterization of Graded Soil T2 - Proceedings of the 6th International Conference on Scour and Erosion (ICSE-6) Y1 - 2012 SP - 345 EP - 352 ER - TY - JOUR A1 - Weber, Britta A1 - Greenan, Garrett A1 - Prohaska, Steffen A1 - Baum, Daniel A1 - Hege, Hans-Christian A1 - Müller-Reichert, Thomas A1 - Hyman, Anthony A1 - Verbavatz, Jean-Marc T1 - Automated tracing of microtubules in electron tomograms of plastic embedded samples of Caenorhabditis elegans embryos JF - Journal of Structural Biology Y1 - 2012 UR - http://www.sciencedirect.com/science/article/pii/S1047847711003509 U6 - https://doi.org/10.1016/j.jsb.2011.12.004 VL - 178 IS - 2 SP - 129 EP - 138 ER - TY - JOUR A1 - Kleinfeld, David A1 - Bharioke, Arjun A1 - Blinder, Pablo A1 - Bock, David A1 - Briggman, Kevin A1 - Chklovskii, Dmitri A1 - Denk, Winfried A1 - Helmstaedter, Moritz A1 - Kaufhold, John A1 - Lee, Wei-Chung A1 - Meyer, Hanno A1 - Micheva, Kristina A1 - Oberlaender, Marcel A1 - Prohaska, Steffen A1 - Reid, R. A1 - Smith, Stephen A1 - Takemura, Shinya A1 - Tsai, Philbert A1 - Sakmann, Bert T1 - Large-scale automated histology in the pursuit of connectomes JF - Journal of Neuroscience Y1 - 2011 UR - http://www.zib.de/prohaska/docs/Kleinfeld_JNS_Connectomes_2011.pdf U6 - https://doi.org/10.1523/JNEUROSCI.4077-11.2011 VL - 31 IS - 45 SP - 16125 EP - 16138 ER - TY - JOUR A1 - Lindow, Norbert A1 - Baum, Daniel A1 - Prohaska, Steffen A1 - Hege, Hans-Christian T1 - Accelerated Visualization of Dynamic Molecular Surfaces JF - Comput. Graph. Forum Y1 - 2010 U6 - https://doi.org/10.1111/j.1467-8659.2009.01693.x VL - 29 SP - 943 EP - 952 ER - TY - CHAP A1 - Reininghaus, Jan A1 - Günther, David A1 - Hotz, Ingrid A1 - Prohaska, Steffen A1 - Hege, Hans-Christian T1 - TADD: A Computational Framework for Data Analysis Using Discrete Morse Theory T2 - Mathematical Software - ICMS 2010 Y1 - 2010 U6 - https://doi.org/10.1007/978-3-642-15582-6_35 VL - 6327 SP - 198 EP - 208 PB - Springer ER - TY - JOUR A1 - Kuß, Anja A1 - Gensel, Maria A1 - Meyer, Björn A1 - Dercksen, Vincent J. A1 - Prohaska, Steffen T1 - Effective Techniques to Visualize Filament-Surface Relationships JF - Comput. Graph. Forum Y1 - 2010 VL - 29 SP - 1003 EP - 1012 ER - TY - GEN A1 - Homberg, Ulrike A1 - Baum, Daniel A1 - Wiebel, Alexander A1 - Prohaska, Steffen A1 - Hege, Hans-Christian ED - Bremer, Peer-Timo ED - Hotz, Ingrid ED - Pascucci, Valerio ED - Peikert, Ronald T1 - Definition, Extraction, and Validation of Pore Structures in Porous Materials BT - Theory, Algorithms, and Applications T2 - Topological Methods in Data Analysis and Visualization III Y1 - 2014 U6 - https://doi.org/10.1007/978-3-319-04099-8_15 SP - 235 EP - 248 PB - Springer ER - TY - CHAP A1 - Rosanwo, Olufemi A1 - Petz, Christoph A1 - Prohaska, Steffen A1 - Hotz, Ingrid A1 - Hege, Hans-Christian ED - Eades, Peter ED - Ertl, Thomas ED - Shen, Han-Wei T1 - Dual Streamline Seeding T2 - Proceedings of the IEEE Pacific Visualization Symposium Y1 - 2009 SP - 9 EP - 16 CY - Beijing, China ER - TY - CHAP A1 - Homberg, Ulrike A1 - Binner, Richard A1 - Prohaska, Steffen A1 - Dercksen, Vincent J. A1 - Kuß, Anja A1 - Kalbe, Ute T1 - Determining Geometric Grain Structure from X-Ray Micro-Tomograms of Gradated Soil T2 - Workshop Internal Erosion Y1 - 2009 VL - 21 SP - 37 EP - 52 ER - TY - CHAP A1 - Paetsch, Olaf A1 - Baum, Daniel A1 - Prohaska, Steffen A1 - Ehrig, Karsten A1 - Meinel, Dietmar A1 - Ebell, Gino T1 - 3D Corrosion Detection in Time-dependent CT Images of Concrete T2 - DIR-2015 Proceedings N2 - In civil engineering, the corrosion of steel reinforcements in structural elements of concrete bares a risk of stability-reduction, mainly caused by the exposure to chlorides. 3D computed tomography (CT) reveals the inner structure of concrete and allows one to investigate the corrosion with non-destructive testing methods. To carry out such investigations, specimens with a large artificial crack and an embedded steel rebar have been manufactured. 3D CT images of those specimens were acquired in the original state. Subsequently three cycles of electrochemical pre-damaging together with CT imaging were applied. These time series have been evaluated by means of image processing algorithms to segment and quantify the corrosion products. Visualization of the results supports the understanding of how corrosion propagates into cracks and pores. Furthermore, pitting of structural elements can be seen without dismantling. In this work, several image processing and visualization techniques are presented that have turned out to be particularly effective for the visualization and segmentation of corrosion products. Their combination to a workflow for corrosion analysis is the main contribution of this work. Y1 - 2015 UR - http://www.ndt.net/events/DIR2015/app/content/Paper/36_Paetsch.pdf ER - TY - GEN A1 - Homberg, Ulrike A1 - Baum, Daniel A1 - Wiebel, Alexander A1 - Prohaska, Steffen A1 - Hege, Hans-Christian T1 - Definition, Extraction, and Validation of Pore Structures in Porous Materials N2 - An intuitive and sparse representation of the void space of porous materials supports the efficient analysis and visualization of interesting qualitative and quantitative parameters of such materials. We introduce definitions of the elements of this void space, here called pore space, based on its distance function, and present methods to extract these elements using the extremal structures of the distance function. The presented methods are implemented by an image processing pipeline that determines pore centers, pore paths and pore constrictions. These pore space elements build a graph that represents the topology of the pore space in a compact way. The representations we derive from μCT image data of realistic soil specimens enable the computation of many statistical parameters and, thus, provide a basis for further visual analysis and application-specific developments. We introduced parts of our pipeline in previous work. In this chapter, we present additional details and compare our results with the analytic computation of the pore space elements for a sphere packing in order to show the correctness of our graph computation. T3 - ZIB-Report - 13-56 Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-42510 SN - 1438-0064 ER - TY - GEN A1 - Homberg, Ulrike A1 - Baum, Daniel A1 - Prohaska, Steffen 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 fluids. 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 $\mu$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. T3 - ZIB-Report - 17-26 KW - trabecular structures KW - image-based analysis KW - additive manufacturing KW - printability Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-64004 SN - 1438-0064 ER - TY - JOUR A1 - Redemann, Stefanie A1 - Baumgart, Johannes A1 - Lindow, Norbert A1 - Shelley, Michael A1 - Nazockdast, Ehssan A1 - Kratz, Andrea A1 - Prohaska, Steffen A1 - Brugués, Jan A1 - Fürthauer, Sebastian A1 - Müller-Reichert, Thomas T1 - C. elegans chromosomes connect to centrosomes by anchoring into the spindle network JF - Nature Communications N2 - The mitotic spindle ensures the faithful segregation of chromosomes. Here we combine the first large-scale serial electron tomography of whole mitotic spindles in early C. elegans embryos with live-cell imaging to reconstruct all microtubules in 3D and identify their plus- and minus-ends. We classify them as kinetochore (KMTs), spindle (SMTs) or astral microtubules (AMTs) according to their positions, and quantify distinct properties of each class. While our light microscopy and mutant studies show that microtubules are nucleated from the centrosomes, we find only a few KMTs directly connected to the centrosomes. Indeed, by quantitatively analysing several models of microtubule growth, we conclude that minus-ends of KMTs have selectively detached and depolymerized from the centrosome. In toto, our results show that the connection between centrosomes and chromosomes is mediated by an anchoring into the entire spindle network and that any direct connections through KMTs are few and likely very transient. Y1 - 2017 U6 - https://doi.org/10.1038/ncomms15288 VL - 8 IS - 15288 ER - TY - JOUR A1 - Homberg, Ulrike A1 - Baum, Daniel A1 - Prohaska, Steffen A1 - Günster, Jens A1 - Krauß-Schüler, Stefanie T1 - Adapting trabecular structures for 3D printing: an image processing approach based on µCT data JF - Biomedical Physics & Engineering Express N2 - Materials with a trabecular structure notably combine advantages such as lightweight, reasonable strength, and permeability for fluids. 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 $\mu$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. Y1 - 2017 U6 - https://doi.org/10.1088/2057-1976/aa7611 VL - 3 IS - 3 PB - IOP Publishing ER - TY - GEN A1 - Zhukova, Yulia A1 - Hiepen, Christian A1 - Knaus, Petra A1 - Osterland, Marc A1 - Prohaska, Steffen A1 - Dunlop, John W. C. A1 - Fratzl, Peter A1 - Skorb, Ekaterina V. T1 - The role of titanium surface nanotopography on preosteoblast morphology, adhesion and migration N2 - Surface structuring of titanium-based implants with appropriate nanotopographies can significantly modulate their impact on the biological behavior of cells populating these implants. Implant assisted bone tissue repair and regeneration require functional adhesion and expansion of bone progenitors. The surface nanotopography of implant materials used to support bone healing and its effect on cell behavior, in particular cell adhesion, spreading, expansion, and motility, is still not clearly understood. The aim of this study is to investigate preosteoblast proliferation, adhesion, morphology, and migration on different titanium materials with similar surface chemistry, but distinct nanotopographical features. Sonochemical treatment and anodic oxidation were employed to fabricate disordered – mesoporous titania (TMS), and ordered – titania nanotubular (TNT) topographies respectively. The morphological evaluation revealed a surface dependent shape, thickness, and spreading of cells owing to different adherence behavior. Cells were polygonal-shaped and well-spread on glass and TMS, but displayed an elongated fibroblast-like morphology on TNT surfaces. The cells on glass however, were much flatter than on nanostructured surfaces. Both nanostructured surfaces impaired cell adhesion, but TMS was more favorable for cell growth due to its support of cell attachment and spreading in contrast to TNT. Quantitative wound healing assay in combination with live-cell imaging revealed that cells seeded on TMS surfaces migrated in close proximity to neighboring cells and less directed when compared to the migratory behavior on other surfaces. The results indicate distinctly different cell adhesion and migration on ordered and disordered titania nanotopographies, providing important information that could be used in optimizing titanium-based scaffold design to foster bone tissue growth and repair. T3 - ZIB-Report - 17-06 Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-63053 SN - 1438-0064 ER - TY - JOUR A1 - Paetsch, Olaf A1 - Baum, Daniel A1 - Prohaska, Steffen A1 - Ehrig, Karsten A1 - Ebell, Gino A1 - Meinel, Dietmar A1 - Heyn, Andreas T1 - Korrosionsverfolgung in 3D-computertomographischen Aufnahmen von Stahlbetonproben JF - DGZfP-Jahrestagung 2014 Konferenzband Y1 - 2014 ER - TY - JOUR A1 - Knötel, David A1 - Seidel, Ronald A1 - Prohaska, Steffen A1 - Dean, Mason N. A1 - Baum, Daniel T1 - Automated Segmentation of Complex Patterns in Biological Tissues: Lessons from Stingray Tessellated Cartilage JF - PLOS ONE N2 - Introduction – Many biological structures show recurring tiling patterns on one structural level or the other. Current image acquisition techniques are able to resolve those tiling patterns to allow quantitative analyses. The resulting image data, however, may contain an enormous number of elements. This renders manual image analysis infeasible, in particular when statistical analysis is to be conducted, requiring a larger number of image data to be analyzed. As a consequence, the analysis process needs to be automated to a large degree. In this paper, we describe a multi-step image segmentation pipeline for the automated segmentation of the calcified cartilage into individual tesserae from computed tomography images of skeletal elements of stingrays. Methods – Besides applying state-of-the-art algorithms like anisotropic diffusion smoothing, local thresholding for foreground segmentation, distance map calculation, and hierarchical watershed, we exploit a graph-based representation for fast correction of the segmentation. In addition, we propose a new distance map that is computed only in the plane that locally best approximates the calcified cartilage. This distance map drastically improves the separation of individual tesserae. We apply our segmentation pipeline to hyomandibulae from three individuals of the round stingray (Urobatis halleri), varying both in age and size. Results – Each of the hyomandibula datasets contains approximately 3000 tesserae. To evaluate the quality of the automated segmentation, four expert users manually generated ground truth segmentations of small parts of one hyomandibula. These ground truth segmentations allowed us to compare the segmentation quality w.r.t. individual tesserae. Additionally, to investigate the segmentation quality of whole skeletal elements, landmarks were manually placed on all tesserae and their positions were then compared to the segmented tesserae. With the proposed segmentation pipeline, we sped up the processing of a single skeletal element from days or weeks to a few hours. Y1 - 2017 U6 - https://doi.org/10.1371/journal.pone.0188018 ER - TY - GEN A1 - Knötel, David A1 - Seidel, Ronald A1 - Zaslansky, Paul A1 - Prohaska, Steffen A1 - Dean, Mason N. A1 - Baum, Daniel T1 - Automated Segmentation of Complex Patterns in Biological Tissues: Lessons from Stingray Tessellated Cartilage (Supplementary Material) N2 - Supplementary data to reproduce and understand key results from the related publication, including original image data and processed data. In particular, sections from hyomandibulae harvested from specimens of round stingray Urobatis halleri, donated from another study (DOI: 10.1002/etc.2564). Specimens were from sub-adults/adults collected by beach seine from collection sites in San Diego and Seal Beach, California, USA. The hyomandibulae were mounted in clay, sealed in ethanol-humidified plastic tubes and scanned with a Skyscan 1172 desktop μCT scanner (Bruker μCT, Kontich, Belgium) in association with another study (DOI: 10.1111/joa.12508). Scans for all samples were performed with voxel sizes of 4.89 μm at 59 kV source voltage and 167 μA source current, over 360◦ sample 120 rotation. For our segmentations, the datasets were resampled to a voxel size of 9.78 μm to reduce the size of the images and speed up processing. In addition, the processed data that was generated with the visualization software Amira with techniques described in the related publication based on the mentioned specimens. Y1 - 2017 U6 - https://doi.org/10.12752/4.DKN.1.0 N1 - Supplementary data to reproduce and understand key results from the related publication, including original image data and processed data. ER - TY - GEN A1 - Lindow, Norbert A1 - Redemann, Stefanie A1 - Fabig, Gunar A1 - Müller-Reichert, Thomas A1 - Prohaska, Steffen T1 - Quantification of Three-Dimensional Spindle Architecture N2 - Mitotic and meiotic spindles are microtubule-based structures to faithfully segregate chromosomes. Electron tomography is currently the method of choice to analyze the three-dimensional architecture of both types of spindles. Over the years, we have developed methods and software for automatic segmentation and stitching of microtubules in serial sections for large-scale reconstructions. Three-dimensional reconstruction of microtubules, however, is only the first step towards biological insight. The second step is the analysis of the structural data to derive measurable spindle properties. Here, we present a comprehensive set of techniques to quantify spindle parameters. These techniques provide quantitative analyses of specific microtubule classes and are applicable to a variety of tomographic reconstructions of spindles from different organisms. T3 - ZIB-Report - 18-07 Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-66562 SN - 1438-0064 ER -