Cerebral Aneuryms: Visualization of Scalar Wall Shear Stress… [more]
“Combined Visualization of Wall Thickness and Wall Shear Stress for the Evaluation of Aneurysms”
Sylvia Glaßer, Kai Lawonn, Thomas Hoffmann, Martin Skalej, Bernhard Preim.
“Interactive Visual Analysis of Image-Centric Cohort Study Data” Paul Klemm, Steffen Oeltze-Jafra, Kai Lawonn, Katrin Hegenscheid, Henry Völzke, Bernhard Preim
“Blood Flow Clustering and Applications in Virtual Stenting of Intracranial Aneurysms” Steffen Oeltze, Dirk J. Lehmann, Alexander Kuhn, Gabor Janiga, Holger Theisel, Bernhard Preim.
“ADR - Anatomy-Driven Reformation” Jan Kretschmer, Grzegorz Soza, Christian Tietjen, Michael Suehling, Bernhard Preim, Marc Stamminger
We look forward to it!
04/07/2014: Phd Thesis defended
Sylvia Glaßer, Phd student of the visualization group, successfully defended her thesis “Visual Analysis, Clustering, and Classification of Contrast-Enhanced Tumor Perfusion MRI Data”.
25/06/2014: Phd Thesis defended
Mathias Neugebauer, Phd student of the visualization group, successfully defended his thesis “Computer-Aided Exploration of Blood Flow in Cerebral Aneurysms – Geometrical Processing and Interactive Visualization”.
12/06/2014: Honorable Mention
Our joint work with SIEMENS Healthcare and the University of Erlangen was awarded with the only Honorable Mention award in the EuroVis Short Paper Section, making it the 2nd best Short Paper. The paper deals with an improved multivessel reformation technique based on a bilateral filter applied to depth information that effectively avoids small and disturbing discontinuities while preserving large information-carrying discontinuities. Bernhard Preim gets the award from one of the Short Paper Chairs in Swansea.
12/06/2014: New Phd Student
We are happy that Patrick Saalfeld got a grant for a Phd program from our local government to do research on 3D interaction related to treatment planning problems, such as implant placement and applicator positioning.
25/04/2014: CG&A paper on “Interactive Visual Analysis of Heterogeneous Cohort Study Data” accepted for publication
Paolo Angelelli from the Visualization research group of the University of Bergen, Norway visited our group in October/November 2011. His visit initiated a long-term collaboration on investigating longitudinal medical and cohort studies between the Visualization group in Bergen (Paolo Angelelli, Cagatay Turkay, and Helwig Hauser), the Department of Biomedicine (Judit Haáasz, Erlend Hodneland and Arvid Lundervold) and the Department of Biological and Medical Psychology (Astri J. Lundervold) at the University of Bergen, and our Visualization group (Steffen Oeltze-Jafra, Bernhard Preim). In the paper resulting from this long-term effort, we demonstrate the interactive visual exploration and analysis of cohort study data, helping with the generation of new hypotheses and contributing to the process of validating them. We propose a data-cube based model which handles partially overlapping data subsets during the interactive visualization. We implemented this model in an application prototype, and used it to analyze data acquired in the context of a Norwegian cohort study on cognitive aging. A pre-print of the paper is available here: http://dx.doi.org/10.1109/MCG.2014.40.
25/04/2014: IEEE TVCG paper on “Blood Flow Clustering and Applications in Virtual Stenting of Intracranial Aneurysms” appeared online and will be presented at this year's IEEE VIS (Paris, France)
Flow data resulting from steady-state simulations of blood flow in cerebral aneurysms are generally visualized by a dense and cluttered set of streamlines. The paper describes a fully automatic approach for reducing visual clutter and exposing characteristic flow structures by clustering streamlines and computing cluster representatives. While individual clustering techniques have been applied before to streamlines in 3D flow fields, a general quantitative and a domain-specific qualitative evaluation of three state-of-the-art techniques are contributed. It is shown that clustering streamlines contributes to comparing and evaluating different virtual stenting strategies. The paper is the result of a collaboration between our Visualization group (Steffen Oeltze-Jafra, Bernhard Preim), the Institute of Fluid Dynamics and Thermodynamics of our University (Gábor Janiga), the Visual Computing group (Dirk J. Lehmann, Alexander Kuhn, Holger Theisel), and the Institute of Neuroradiology of our University Hospital (Oliver Beuing). It is available here: http://dx.doi.org/10.1109/TVCG.2013.2297914. The accompanying video can be found here: http://www.youtube.com/watch?v=-RVVgqDHzdc.
11/04/2014: New PhD submission
Kai Lawonn has submitted his Phd thesis “Illustrative Visualization of Medical Data Sets” after a record time of 2 years and 4 months. As a mathematician, Kai soon become familiar with shader programming and advanced visualization techniques enabling him to make a number of strong contributions in illustrative and medical visualization. Among these contributions is a new method to generate smooth yet precise cutting lines based on an initial user-defined line, a substantial comparison of feature line techniques, the introduction of a new technique combining advantages of features lines and hatchings as well as improved smart visibility techniques to display vascular surfaces and embedded (simulated) blood flow. Also Kai was the first to display endoscopic views with feature lines and discussed pros and cons of their use.
Simon Adler, external Phd student of the visualization group, successfully defended his thesis on surgery simulation. Simon developed methods to efficiently cut in tetrahedral meshes, to deform organs and vascular structures.
We are happy that two submissions of our group were accepted at EuroVis in Swansea (http://eurovis.swansea.ac.uk).
The paper “Line Integral Convolution for Real-Time Illustration of Molecular Surface Shape and Salient Regions” was prepared by Kai Lawonn. It is a joint work with the Visualization group at University of Stuttgart where molecular dynamics simulations are carried out.
The paper “Comparative Blood Flow Visualization for Cerebral Aneurysm Treatment Assessment” is a result of our long-term effort to explore blood flow and to support neurovascular interventions. Rocco Gasteiger collaborated (again) with Roy van Pelt from Technical University of Eindhoven.
07/02/2014: Phd Thesis defended
Rocco Gasteiger successfully defended his PhD thesis on Visual Exploration of Cardiovascular Hemodynamics with summa cum laude at 07 February 2014. Rocco developed methods for expressive renderings of blood flow vessels with embedded flow information, to quantify the flow with respect to the inflow jet and the impingement zone in cerebral aneurysms as well as new exploration techniques, such as his FlowLens. During his PhD he collaborates very effectively with members from the group of Visual Computing, the Institute of Neuroradiology at the university hospital of Magdeburg, the Institute of Fluid Dynamics and Thermodynamics, the Department of Biomedical Magnetic Resonance as well as the Department of BioMedical Engineering at the Technical University of Eindhoven. Some visual impressions from the defense ceremony and party can be found here.
14/01/2014: New PhD submission
Mathias Neugebauer submitted his PhD thesis „Computergestützte Exploration von zerebralen Aneurysmen – Geometrische Verarbeitung und interaktive Visualisierung“. In his work he describes various approaches for an anatomy-driven qualitative, visual exploration of flow in cerebral aneurysms. By reducing the spatial complexity and the usage of application-driven user interfaces and guided interaction, Mathias aims at bridging the gap between two expert domains: flow simulation and neuroradiology. Parts of this work were developed as part of MoBeStAn (“Modellierung und Beeinflussung von Strömung in zerebralen Aneurysmen”), a government-funded, interdisciplinary project.
14/01/2014: New PhD submission
Tobias Mönch submitted his PhD thesis “Context-Aware 3D Model Generation for Biomedical Applications”. As a part of the BMBF-funded project “ViERforES”, Tobias analyzed the generation of anatomic surface models w.r.t. artifact reduction in the scope of characteristic medical applications, such as surgical planning and simulation, blood flow simulation, and rapid prototyping. By employing context knowledge on these specific applications and data, he developed new methods which improve the robustness of existing mesh smoothing filters and allow for a better preservation of the model quality.
19/12/2013: Second Edition “Visualization in Medicine”
Dec. 13: The second edition of the book “Visualization in Medicine” has appeared at Elsevier. The slightly changed title “Visual Computing in Medicine” reflects that image analysis, human-computer interaction and simulation play a greater role. The whole content is completely updated. In addition to the printed book, five chapters are available freely online.
18/12/2013: New PhD submission
Sylvia Glaßer submitted her PhD thesis “Visual Analysis, Clustering, and Classification of Contrast-Enhanced Tumor Perfusion MRI Data”. The thesis was realized as part of the DFG priority programme “Scaleable Visual Analytics”. Sylvia analyzed breast and brain tumor perfusion data combining automatic data analysis techniques and visual exploration for a more reliable discrimination of malignant and benign tumors.
We are happy that our four submissions for the workshop on image processing in medicine were accepted for presentation.
The paper “Adapted Spectral Clustering for Evaluation and Classification of DCE-MRI Breast Tumors” by Sylvia Glaßer and colleagues introduces a spectral clustering approach for breast tumor data. The clustering parameters are automatically derived such that the clustering results can be employed for an automatic classification into benign and malignant breast lesions.
The paper “Socio-demographic and Medical Attribute Data in Cohort Studies” by Paul Klemm and colleagues proposes an alternative approach for analyzing significant interactions for identifying risk factors in epidemiological cohort study data by incorporating clustering algorithms with a Visual Analytics system to form subject groups. This is the basis for an exploratory analysis of the underlying parameter interactions. With the presented system, groups can be automatically determined to provide insights into this complex data.
The paper “Illustrative Visualization of Endoscopic Views” was prepared by Kai Lawonn and colleagues and deals with the application of illustrative line renderings on endoscopic views. Different line drawing concepts were examined and the ability to represent interior branches as well as specific anatomic features was assessed.
The paper “Measurement of the Stratum Radiatum/Lacunosum-Moleculare (SRLM)” was prepared by Steffen Oeltze and colleagues. Alzheimer disease (AD) at an early stage is characterized by a synaptic loss and atrophy in the apical layer of the CA1 part of the hippocampus, the stratum radiatum and stratum lacunosum-moleculare (SRLM). In cooperation with the Institute of Cognitive Neurology and Dementia Research at the University of Magdeburg and the German Center for Neurodegenerative Diseases (Standort Magdeburg) a new approach to measuring SRLM thickness in 7Tesla MR-images was developed.
23/09/2013: New PhD submission
Rocco Gasteiger submitted his Phd thesis today. Starting in 2007 and sometimes side-tracked by other projects he had to take care of, Rocco dealt with the exploration of measured and simulated blood flow data, comparing results, developing new exploration techniques, such as his FlowLens. In a close cooperation with Roy van Pelt and Anna Vilanova , Rocco developed techniques to quantify the flow with respect to the inflow jet and the impingement zone. Besides his two most essential papers that appeared at IEEE TVCG, another contribution of Rocco is extraordinary: a new approach to depict the vascular morphology and internal flow, published at the VCBM Eurographics Workshop in 2010 and being effectively the most heavily cited paper.
Kai Lawonn’s work about adaptive surface visualization of vessels with embedded blood flow has been selected as one of the three best papers in the VMV 2013 conference. The work will be presented in an extended version at Computer Graphics Forum.
We are happy that our tutorial submission entitled “Interactive Visual Analysis of Scientific Data” has been accepted as a half-day tutorial for VisWeek 2013. The tutorial is a collaborative effort of Helwig Hauser from the University of Bergen, Norway, Johannes Kehrer from the Vienna University of Technology, Austria, and Steffen Oeltze (organizer). The tutorial has been held once before at VisWeek 2012. The notes of last year are available at: http://www.vismd.de/doku.php?id=teaching_tutorials:start. This year, the tutorial has been significantly changed, e.g., to present new application fields of Interactive Visual Analysis (IVA) to the audience: IVA of epidemiological and flow data.
8/08/2013: VisGroup@IEEE VisWeek
We are happy that the two submissions for the SciVis conference within IEEE VisWeek (http://ieeevis.org/) were accepted for presentation.
The paper “Semi-Automatic Vortex Extraction in 4D PC-MRI Cardiac Blood Flow Data using Line Predicates”
was prepared by Ben Köhler and colleagues and represents the major results of Ben's Master thesis. Features of measured cardiac blood flow are related to severe pathologies. This work was only possible with substantial support from the Herzzentrum Leipzig (Prof. Gutberlet, Dr. Uta Preim) who provided these very special kind of data and greatly helped to interpret them and guide the analysis towards clinically relevant features.
Jan Kretschmar (SIEMENS Forchheim and Phd student in Erlangen) prepared a paper “Interactive Patient-Specific Vascular Modeling with Sweep Surfaces”
on the creation of vascular surfaces models that are not only smooth and accurate but also appropriate for blood flow simulation. We could slightly contribute to Jan's work and extend the cooperation that already lead to a EuroVis paper last year.
8/08/2013: New CGF paper on “Mesh Smoothing” appeared online (July 30)
After the presentation at VCBM in Norrköping 2012, Tobias Mönch was invited to prepare an enhanced article for the Computer Graphics Forum on the framework for interactive mesh smoothing, primarily for anatomical surface models. After careful reviewing, the paper was now accepted and appeared online http://onlinelibrary.wiley.com/doi/10.1111/cgf.12165/abstract.
It represents the highlight of Tobias' upcoming Phd thesis. The paper was joint work with Kai Lawonn, Christoph Kubisch (nVidia) and Rüdiger Westermann (TU Munich) who contributed to algorithmic descriptions and efficient hardware implementation.
1/06/2013: Many interested visitors at the “Long Night of Science”
Around 1300 visitors attended the “Long Night of Science” on June 1st, 2013 at the Faculty of Computer Science. Not only on June 1st, but also during the Campus Days (held on May, 31 and June, 1st), the Visualization group presented current research work on “Medical 3D Visualization and Interaction for Therapy Planning”.
21/05/2013: Dirk Bartz Medical Prize received
We are happy to announce that members of the visualization group were awarded with the 2nd prize of the Dirk Bartz Prize for Visual Computing in Medicine 2013. The entry was titled “Interactive Visual Exploration of Hemodynamics in Cerebral Aneurysms” and it summarizes the work of Mathias Neugebauer, Rocco Gasteiger, Gabor Janiga (ISUT), Oliver Beuing (Radiology Dept. University Hospital), and Bernhard Preim. The award ceremony was part of this year’s EuroGraphics Award ceremony, in the beautiful Teatre Municipal de Girona (Girona, Spain).
27/04/2013: The Web3D “LiverAnatomyExplorer” was accepted for IEEE Computer Graphics & Applications
Our submission “The LiverAnatomyExplorer: A WebGL-based Surgical Teaching Tool” was accepted for a special issue of IEEE Computer Graphics and Applications on Web-Based 3D visualizations.
The paper describes the design, implementation and evaluation of a liver anatomy system that conveys different variants of the liver anatomy based on 13 datasets. 2D slice-based and 3D visualizations with a number of interaction techniques to explore the data are provided. State-of-the-art Web3D technologies and frameworks, like WebGL and X3DOM, are employed to provide a solution without any plugins. In contrast to other web-based training systems, the LiverAnatomyExplorer is based on a representative set of cases and provides more interactive features.
The paper was authored by Steven Birr, Jeanette Mönch, Uta and Bernhard Preim.
26/03/2013: Vis-Group at EuroVis 2013
We are happy that two of our submissions for the EuroVis conference in Leipzig were finally accepted and will appear in the Computer Graphics Forum.
Kai Lawonn is the principal author of the paper “Streamlines for Illustrative Real-time Rendering” where he suggests a new method to place lines on surfaces of complex (anatomical) surface models. These lines are seeded along curvature-related vector fields and provide more shape information than conventional feature lines. The line generation process, including curvature estimation, as well as the efficient rendering is described in the paper.
Mathias Neugebauer introduced “AmniVis - A System for Qualitative Exploration of Near-Wall Hemodynamics in Cerebral Aneurysms”. The paper is based on many in-depth discussions with neuroradiologists and aims to present results of unsteady (time-dependent) CFD simulations intuitively and effectively. Essential questions, guiding this research, are: How can the user efficiently select relevant time steps? What features are particularly interesting? How they can be emphasized and assessed?
15/03/2013: 10 Jahre Visualisierung in Magdeburg
Die Arbeitsgruppe “Medizinische Visualisierung” an der Universität Magdeburg feiert ihr 10-jähriges Bestehen. Aus diesem Anlass wird es am 26. April 2013 ab 15 Uhr im Hörsaal der Fakultät für Informatik (G29-307) ein Symposium geben, bei dem ein kleiner Einblick in die vergangenen 10 Jahre und in die Arbeiten der Arbeitsgruppe, ehemaliger Mitarbeiter und eng verbundener Partner gegeben wird. Mehr Informationen...
On January 30, the kick-off event for the research campus STIMULATE (Solution Centre for Image guided local Therapies) takes place, see the schedule:
The research campus is a joint activity between our University, SIEMENS Healthcare as well as a number of associated companies.
15/03/2013: 10 Jahre AG Visualisierung
09/18/2010: “Karl-Heinz-Höhne MedVis-Award”
“Nachwuchswissenschaftler für ihre Arbeit geehrt - Computerunterstützung für die klinische Anwendung”
Die Fachgruppe “Visual Computing in der Medizin” der Gesellschaft für Informatik vergibt am 18. November 2010 zum vierten Mal den Karl-Heinz-Höhne MedVis-Award, für den das Münchener Medizintechnikunternehmen BrainLAB AG das Preisgeld stiftete.
Ausgezeichnet wurden Nachwuchswissenschaftler, die mit ihren Arbeiten einen wichtigen Beitrag für die Nutzung bildgebender Verfahren in der Diagnostik und Therapie geleistet haben. Eine Jury aus 15 Experten, geleitet von Bernhard Preim (Universität Magdeburg) und Stefan Zachow (Zuse-Institut Berlin) hat die 18 eingereichten Arbeiten sorgfältig bewertet und verglichen.
Mit dem 1. Preis wird Christian Dick, Technische Universität München geehrt. Ihm ist es gelungen, biomechanische Simulationen mit der interaktiven Darstellung von CT-Daten zu kombinieren, um damit orthopädische Operationen, speziell an der Hüfte besser planen zu können. Seine Simulationsmethode nutzt dabei die programmierbare Grafikhardware und ist dadurch um Größenordnungen schneller als bisherige Verfahren - so dass die Simulationen erstmals direkt im Rahmen einer interaktiven Planung eingesetzt werden können.
Mit dem 2. Preis wurde Christian Rieder, Fraunhofer MEVIS Bremen, geehrt. Seine Arbeit dient vor allem der Planung von Tumoroperationen im Gehirn und an der Leber. Er kombiniert dabei verschiedene Darstellungstechniken geschickt und ermöglicht so, die Integration aller relevanten Informationen in aussagekräftigen 3D-Visualisierungen. So sehen die Mediziner z.B. besser, wie sie eine Applikatornadel platzieren können, die den Tumor durch Wärmewirkung bei Anwendung der Radiofrequenztherapie zerstören soll.
Aufgrund der besonders hohen Qualität der eingereichten Beiträge wurden zwei 3. Preise vergeben.
Dagmar Kainmüller vom Zuse-Institut Berlin wird für ihre Arbeit zur automatischen Segmentierung von anatomischen Strukturen ausgezeichnet. Vereinfacht gesagt, gelingt es ihr durch eine komplizierte mathematische Modellierung von anatomischen Formen und Bildinformationen, eine Struktur, z.B. ein Organ in einem Datensatz automatisch korrekt abzugrenzen. Solche Segmentierungsmethoden sind meist die Voraussetzung für die Generierung aussagekräftiger Visualisierungen der 3D-Anatomie.
Konrad Mühler, Universität Magdeburg, hat eine Vielzahl von Algorithmen, z.B. zur automatischen Beschriftung von medizinischen 3D-Modellen entwickelt und in eine frei verfügbare Software-bibliothek zur Implementierung medizinischer Visualisierungskomponenten integriert. Andere Entwickler müssen somit “das Rad nicht immer wieder neu erfinden.” Die Preisverleihung findet auf der Jahrestagung der “Deutschen Gesellschaft für Computer- und Roboterassistierte Chirurgie” (CURAC) in Düsseldorf statt.”