Ivo Rössling
Publications
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The Tumor Therapy Manager -- Design, Refinement and Clinical Use of a Software Product for ENT Surgery Planning and Documentation
Information Processing in Computer-Assisted Interventions (IPCAI), Berlin; 01/2011
The treatment of patients with head and neck cancers is a demanding medical field, due to the compact anatomy and complex functionality of the affected region. The planning process comprises issues regarding risk and applicability of intervention, extent of surgical removal, and the choice of approp... [more] The treatment of patients with head and neck cancers is a demanding medical field, due to the compact anatomy and complex functionality of the affected region. The planning process comprises issues regarding risk and applicability of intervention, extent of surgical removal, and the choice of appropriate access to the pathology. Required clinical information are obtained from different examinations, ranging from external visual and palpatory inspection, over preoperative panendoscopy and biopsy histology to radiological imaging. The surgeon needs to process all available information in mind and virtually compile a mental patient model of the target anatomy. 3D visualizations of tomographic data may improve perception of spatial relationships. However, discussions with clinical practicians reveal that parameterization of advanced visual effects tend to be cumbersome and resulting visualizations are often too complex and not dedicated to specific diagnostic or treatment planning questions. Moreover, th
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The Tumor Therapy Manager and its Clinical Impact
EuroGraphics, Llandudno; 01/2011
Visual exploration of CT and MRI datasets in clinical practice is still dominated by slice-based viewing. Volume rendering is now widely available but seen primarily as a tool for a fast overview, and only rarely as a visualization to directly support clinical decisions. Research projects aiming at ... [more] Visual exploration of CT and MRI datasets in clinical practice is still dominated by slice-based viewing. Volume rendering is now widely available but seen primarily as a tool for a fast overview, and only rarely as a visualization to directly support clinical decisions. Research projects aiming at advanced 3D visualizations, such as smart visibility and illustrative renderings, usually fail to meet clinical demands, since the visualizations are not dedicated to specific diagnostic or treatment planning questions. Moreover, they are unfamiliar to users who need reliable and familiar visualizations as a basis for their crucial decisions. Discussions with clinical practicians reveal that parameterization of visual effects is too cumbersome and resulting visualizations are often too complex. We describe and discuss long-term experiences on developing, testing, and refining image analysis and visualization techniques for ENT surgery planning based on CT data. While visual quality and a faithful renditi
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Erzeugung und Simulation eines dynamischen 3D-Modells der Kopf-Hals-Region aus CT-Daten.
Bildverarbeitung für die Medizin 2009: Algorithmen - Systeme - Anwendungen, Proceedings des Workshops vom 20. bis 22. März 2011 in Lübeck; 01/2011
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On Design and Implementation of a Generic Number-Type for Real Algebraic Number Computations Based on Expression Dags
Mathematics in Computer Science. 01/2011;
We report on the design and implementation of a number type called Real_algebraic. This number type allows us to compute the correct sign of arithmetic expressions involving the operations +, -, *, / , d-th root. The sign computation is always correct and, in this sense, not subject to rounding erro... [more] We report on the design and implementation of a number type called Real_algebraic. This number type allows us to compute the correct sign of arithmetic expressions involving the operations +, -, *, / , d-th root. The sign computation is always correct and, in this sense, not subject to rounding errors. We focus on modularity and use generic programming techniques to make key parts of the implementation easily exchangeable. Thus our design allows for easily performing experiments with different implementations or thereby to tailor the number type for specific tasks. For many problems in computational geometry instantiations of our number type Real_algebraic are a user-friendly alternative for implementing the exact geometric computation paradigm in order to abandon numerical robustness problems
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Interaktive Korrektur Medizinischer Segmentierungen unter Anwendung Effizienter Partitionierungstechniken
14. IFF-Wissenschaftstage, Magdeburg; 01/2011
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Erzeugung und Simulation eines dynamischen 3D-Modells der Kopf-Hals-Region aus CT-Daten
Bildverarbeitung für die Medizin (BVM) 2011, Lübeck; 01/2011
Patientenindividuelle 3D-Modelle von Organen und Körperregionen tragen erheblich zur Dokumentation, Kommunikation und Patientenaufklärung bei. Aus Segmentierungen dreidimensionaler Datensätze (CT, MRT, etc.) gewonnen, kann jedoch nur die statische Pose während der Bildaufnahme abgebildet werden, was... [more] Patientenindividuelle 3D-Modelle von Organen und Körperregionen tragen erheblich zur Dokumentation, Kommunikation und Patientenaufklärung bei. Aus Segmentierungen dreidimensionaler Datensätze (CT, MRT, etc.) gewonnen, kann jedoch nur die statische Pose während der Bildaufnahme abgebildet werden, was eine deutliche Einschränkung z.B. gegenüber den gebräuchlichen annotierbaren Schemazeichnungen mit ihren speziell vordefinierten Ansichten darstellt. In der vorliegenden Arbeit erweitern wir zuvor statische individuelle 3DModelle der Kopf-Hals-Region um die Fähigkeit zu anatomisch möglichen Bewegungen. Neben der Bewegung des Knochenapparates wird auch die gleichzeitig stattfindende Deformation der verbundenen Weichteile berücksichtigt, welche durch Feder-Masse-Modelle modelliert wird. Im Ergebnis zeigen wir einen Software-Prototypen, mit dem aus Segmentierungen automatisch ein dynamisches Patientenmodell der Kopf-Hals-Region erzeugt wird, dessen Strukturen (Knochen, Blutgefäße, Muskeln) in Ech
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Fast and flexible distance measures for treatment planning.
International journal of computer assisted radiology and surgery. 11/2010; 5(6):633-46.
Distance measures are required for diagnoses, therapy decision and documentation. With today's high-resolution CT and MR imaging techniques, high- quality images have become possible. Yet, manual measurement can be tedious. We present a method for automatically determining different distance-bas... [more] Distance measures are required for diagnoses, therapy decision and documentation. With today's high-resolution CT and MR imaging techniques, high- quality images have become possible. Yet, manual measurement can be tedious. We present a method for automatically determining different distance-based measures on segmented anatomic structures, like shortest distances, diameters, and wall thicknesses. Our method is inspired from computational geometry and based on a surface mesh representation. The computation takes all primitives (points, edges, faces) into account and organizes them efficiently in a spatial tree structure. We followed the generic design paradigm in order to achieve maximum flexibility. The generic approach allows for a variety of intervention-relevant distance measures to be computed, using only a single type of data structure. For shortest distance, our approach in empirical tests turned out to be more efficient than previous methods from medical application literature. Besides the numerical value, also its defining geometric primitives are determined. The presented technique is both, fast and flexible. It can be used to interactively derive automatic distance measures for arbitrary mesh-based segmentations. Due to the geometrically exact measurements, it is possible to reliably estimate safety margins, assess possible infiltrations and other clinically relevant measures. To exploit this benefit, the method requires precise segmentations as input data.
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Complete fully automatic model-based segmentation of normal and pathological lymph nodes in CT data.
International journal of computer assisted radiology and surgery. 10/2010; 5(6):565-81.
Exact and reproducible knowledge regarding the position, size, and type of the lymph nodes is often needed for tumor computer-aided diagnosis, treatment planning, and follow-up. An automatic segmentation method for CT data was developed that can identify and delineate normal as well as pathologicall... [more] Exact and reproducible knowledge regarding the position, size, and type of the lymph nodes is often needed for tumor computer-aided diagnosis, treatment planning, and follow-up. An automatic segmentation method for CT data was developed that can identify and delineate normal as well as pathologically altered lymph nodes to satisfy this requirement. A semi-automatic lymph node segmentation method was developed using a 3D Stable Mass-Spring Model (SMSM), based on parallel simulation of the shape model on CT scan images. The models are started across the whole dataset at all potential lymph node positions but will only adapt to the data where a lymph node is found. The node positions can be determined by an evaluation of the model's quality of fit. Systematically chosen lymph nodes in 5 CT datasets, including enlarged, necrotic, fuzzy-bounded, and deformed lymph nodes, were used to evaluate the segmentation algorithm performance. A test set of 29 lymph nodes taken from 4 typical lymph node regions were included. All lymph nodes were detected automatically, while an additional 31% false-positive (n = 9) candidates were detected. The average calculation time was 2 min per dataset. The segmentation accuracy was comparable to the inter-observer variance of human experts. Clinically relevant lymph nodes were detected within a few minutes and provided sufficient accuracy to demonstrate the feasibility of a new segmentation method. The test data were diverse, and the robust results suggest potential applicability to many kinds of lymph node abnormalities, except for extremely degenerated lymph nodes.
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Estimation of the Midsagittal Plane for Sideness Determination of Malignant Structures of Head and Neck
Eurographics Workshop on Visual Computing for Biology and Medicine (EG VCBM), Leipzig; 01/2010
Besides other main criterias like size, infiltration and anatomical district, the sideness of tumor and local metastases (i. e., malignant lymph nodes) is very crucial for head and neck tumor assessment. An automatic sideness determination may speed up tumor staging noticeably. Inspired by prelimina... [more] Besides other main criterias like size, infiltration and anatomical district, the sideness of tumor and local metastases (i. e., malignant lymph nodes) is very crucial for head and neck tumor assessment. An automatic sideness determination may speed up tumor staging noticeably. Inspired by preliminary work of others we present a modified approach for the estimation of the midsagittal plane based on surface meshes. The suitability of the computed result being used in the course of TNM classification was tested in a case study, in terms of an according automatic determination of the sideness for segmented lymph nodes and tumors.
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Schätzung der Midsagittalebene zur Bestimmung der Seitenlage maligner Strukturen des Halses
Bildverarbeitung für die Medizin (BVM), Aachen; 01/2010
Für die Bewerung von Tumoren des Halses spielt neben Kriterien wie Größe, Infiltration und anatomischem Bezirk vor allem auch die Seitenlage des Tumors sowie lokaler Metastasen eine wichtige Rolle. Eine automatische Sondierung der Seitenlage kann das Tumor-Staging stark beschleunigen. Ausgehend von ... [more] Für die Bewerung von Tumoren des Halses spielt neben Kriterien wie Größe, Infiltration und anatomischem Bezirk vor allem auch die Seitenlage des Tumors sowie lokaler Metastasen eine wichtige Rolle. Eine automatische Sondierung der Seitenlage kann das Tumor-Staging stark beschleunigen. Ausgehend von Vorarbeiten Dritter präsentieren wir ein angepasstes Verfahren zur Schätzung der Lage und Ausrichtung der Midsagittalebene basierend auf Oberflächennetzen. Die Eignung des Ergebnisses im Rahmen einer TNM-Klassifikation wird anhand einer darauf basierenden automatischen Bestimmung der Seitenlage segmentierter Lymphknoten oder Tumore überprüft.
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On the Design and Implementation of a Generic Number Type for Real Algebraic Number Computations Based on Expression Dags
Technical Report, Otto-von-Guericke-University; 01/2010
We report on the design and implementation of a number type called Real_algebraic. This number type allows us to compute the correct sign of arithmetic expressions involving the operations +, -, *, / , d-th root. The sign computation is always correct and, in this sense, not subject to rounding erro... [more] We report on the design and implementation of a number type called Real_algebraic. This number type allows us to compute the correct sign of arithmetic expressions involving the operations +, -, *, / , d-th root. The sign computation is always correct and, in this sense, not subject to rounding errors. We focus on modularity and use generic programming techniques to make key parts of the implementation easily exchangeable. Thus our design allows for easily performing experiments with different implementations or thereby to tailor the number type for specific tasks. For many problems in computational geometry instantiations of our number type Real_algebraic are a user-friendly alternative for implementing the exact geometric computation paradigm in order to abandon numerical robustness problems
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Model-based Segmentation of Pathological Lymph Nodes in CT Data
SPIE Medical Imaging, San Diego, California, USA; 01/2010
For the computer-aided diagnosis of tumor diseases knowledge about the position, size and type of the lymph nodes is needed to compute the tumor classification (TNM). For the computer-aided planning of subsequent surgeries like the Neck Dissection spatial information about the lymph nodes is also im... [more] For the computer-aided diagnosis of tumor diseases knowledge about the position, size and type of the lymph nodes is needed to compute the tumor classification (TNM). For the computer-aided planning of subsequent surgeries like the Neck Dissection spatial information about the lymph nodes is also important. Thus, an efficient and exact segmentation method for lymph nodes in CT data is necessary, especially pathological altered lymph nodes play an important role here. Based on prior work, in this paper we present a noticeably enhanced model-based segmentation method for lymph nodes in CT data, which now can be used also for enlarged and mostly well separated necrotic lymph nodes. Furthermore, the kind of pathological variation can be determined automatically during segmentation, which is important for the automatic TNM classification. Our technique was tested on 21 lymph nodes from 5 CT datasets, among several enlarged and necrotic ones. The results lie in the range of the inter-personal variance of
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Distance-Aware Smoothing of Surface Meshes for Surgical Planning
International Workshop on Digital Engineering (IWDE), Magdeburg; 01/2010
The evaluation of spatial relationships between anatomic structures is a major task in surgical planning. Surface models generated from medical image data (intensity, binary) are often used for visualization and 3D measurement of extents and distances between neighboring structures. In applications ... [more] The evaluation of spatial relationships between anatomic structures is a major task in surgical planning. Surface models generated from medical image data (intensity, binary) are often used for visualization and 3D measurement of extents and distances between neighboring structures. In applications for intervention or radiation treatment planning, the surface models need to exhibit a natural look (referring to smoothness of the surface), but also to be accurate. Smoothing algorithms allow to reduce artifacts from mesh generation, but the result is always a tradeoff between smoothness and accuracy. Required features will be removed and distances between adjacent structures get changed. Thus, we present a modification to common mesh smoothing algorithms, which allows to generate smooth surfaces models while distances of neighboring structures are preserved. We compared our distance-aware approach to conventional uniform smoothing methods and evaluated the resulting surface models regarding smoothness and
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Effiziente automatische Bestimmung interventionsrelevanter Entfernungsmaße.
Bildverarbeitung für die Medizin 2009: Algorithmen - Systeme - Anwendungen, Proceedings des Workshops vom 22. bis 25. März 2009 in Heidelberg; 01/2009
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Interaktive Visualisierung von Abständen und Ausdehnungen anatomischer Strukturen für die Interventionsplanung
Bildverarbeitung für die Medizin (BVM), Heidelberg; 01/2009
Im Rahmen der Interventionsplanung muss der Chirurg therapierelevante Entscheidungen auf Basis räumlicher Relationen anatomischer Strukturen treffen. Interaktive 3D-Visualisierungen unterstützen diesen Prozess qualitativ. Quantitative Fragestellungen (Tumorausdehnung, Infiltrationstiefe, etc.) erfor... [more] Im Rahmen der Interventionsplanung muss der Chirurg therapierelevante Entscheidungen auf Basis räumlicher Relationen anatomischer Strukturen treffen. Interaktive 3D-Visualisierungen unterstützen diesen Prozess qualitativ. Quantitative Fragestellungen (Tumorausdehnung, Infiltrationstiefe, etc.) erfordern die Integration einer Bemaßung, deren Nutzen wesentlich von einer geeigneten Darstellung abhängt. In dieser Arbeit haben wir allgemeine Kriterien für die Eignung von Visualisierungen von Bemaßungen in interaktiven 3D-Szenen erarbeitet. Daran orientierend haben wir verschiedene Varianten der Darstellung von Abständen und Ausdehnungen anatomischer Strukturen betrachtet und ihr Erscheinungsbild hierzu zweckmäßig parametrisiert. Die Ausprägungen dieser Darstellungsparameter wurden in einer Studie auf ihre visuellen Wirkung hin an Chirurgen evaluiert. Es zeigte sich, dass die befragten Mediziner höchsten Wert auf Kohärenz und klare Zuordnung der Bemaßung setzten und überraschenderweise dafür sogar Abstriche in der direkten Lesbarkeit in Kauf nahmen.
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Modellbasierte Segmentierung von Halsstrukturen in CT-Daten
Innovations-Forum: Anwendung der Haptik in der robotergestützten Chirurgie (InnFo Haptik), Magdeburg; 01/2009
Die präoperative Planung von Tumoroperationen des Kopf- und Halsbereiches kann durch die dreidimensionale Visualisierung und Quantifizierung der patienten-individuellen Anatomie und Pathologie an Anschaulichkeit und Zuverlässigkeit gewinnen. Ein Hindernis für den routinemäßigen Einsatz derartiger Pl... [more] Die präoperative Planung von Tumoroperationen des Kopf- und Halsbereiches kann durch die dreidimensionale Visualisierung und Quantifizierung der patienten-individuellen Anatomie und Pathologie an Anschaulichkeit und Zuverlässigkeit gewinnen. Ein Hindernis für den routinemäßigen Einsatz derartiger Planungswerkzeuge ist jedoch die erforderliche Segmentierung einer Reihe von Halsstrukturen, die derzeit noch in einem zeitaufwändigen manuellen Prozess erfolgen muss. Insbesondere die Segmentierung länglicher, bzw. komplex geformter anatomischer Strukturen mit uncharakteristischem Grauwertbereich nimmt den größten Zeitaufwand bei der Segmentierung in Anspruch. Dazu zählen im Halsbereich vor allem Knorpel- und Weichgewebestrukturen wie Muskeln (M. sternocleidomastoideus), Kehlkopf (Schild- und Ringknorpel), Blutgefäße (A. carotis, V. jugularis) und pathologisch vergrößerte Lymphknoten. Diese Arbeit stellt daher basierend auf [1] modellbasierte Techniken zur Segmentierung der Lymphknoten und Blutg
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LiSA - A Library Of Scheduling Algorithms
Technical Report, Otto-von-Guericke-University; 01/2003
This technical report reflects the current results in the development of the software package "LiSA - A Library of Scheduling Algorithms". The scientific work of the research group was supported by the Ministry of Culture of the Land Sachsen-Anhalt in the projects "Latin Rectangles in... [more] This technical report reflects the current results in the development of the software package "LiSA - A Library of Scheduling Algorithms". The scientific work of the research group was supported by the Ministry of Culture of the Land Sachsen-Anhalt in the projects "Latin Rectangles in Scheduling Theory" (October 1997 - September 1999) and "LiSA - A Library of Scheduling Algorithms" (November 1999 - October 2001). Within these projects four degree dissertations, three dissertations and one professorial dissertation were produced. LiSA is a software package for solving deterministic scheduling problems. In the version 2.3 LiSA is now prepared for cooperative development. The report gives an overview on the obtained results. Each newcomer will find neccessary information how to work with LiSA, each advancer can use this report as reference book. The LiSA-team, the goals of LiSA, the license and the technical background of the software package are described. A short introduction into the used classification and models is given. An overview on the available algorithms is contained, which can be also used outside of LiSA. An example illustrates how LiSA is working. The LiSA file structure is explained and it is described in detail, how new algorithms can be inserted. Finally, the components of the cooperative development are explained.
Following (11)
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Christine Stroh
Otto-von-Guericke-Universität Magdeburg -
Andreas Nürnberger
Otto-von-Guericke-Universität Magdeburg -
Joeran Beel
Otto-von-Guericke-Universität Magdeburg -
Bernhard Preim
Otto-von-Guericke-Universität Magdeburg -
Coraline Metzger
Otto-von-Guericke-Universität Magdeburg
