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Current blood vessel rendering usually depicts solely the surface of vascular structures and does not visualize any interior structures. While this approach is suitable for most applications, certain cardiovascular diseases, such as aortic dissection would benefit from a more comprehensive visualization. In this work, we investigate different shading styles for the visualization of the aortic inner and outer wall, including the dissection flap. Finding suitable shading algorithms, techniques, and appropriate parameters is time-consuming when practitioners fine-tune them manually. Therefore, we build a shading pipeline using wellknown shading algorithms such as Blinn-Phong, Oren-Nayar, Cook-Torrance, Toon, and extended Lit-Sphere shading with techniques such as the Fresnel effect and screen space ambient occlusion. We interviewed six experts from various domains to find the best combination of shadings for preset combinations that maximize user experience and the applicability in clinical settings., Eurographics Workshop on Visual Computing for Biology and Medicine, The path that blood takes, 107, 111, Kai Ostendorf, Domenico Mastrodicasa, Kathrin Bäumler, Marina Codari, Valery Turner, Martin J. Willemink, Dominik Fleischmann, Bernhard Preim, and Gabriel Mistelbauer, CCS Concepts: Human-centered computing --> Empirical studies in visualization; Applied computing --> Health informatics; Computing methodologies --> Non-photorealistic rendering; Visibility; Reflectance modeling

Breast perfusion data are dynamic medical image data that depict perfusion characteristics of the investigated tissue. These data consist of a series of static datasets that are acquired at different time points and aggregated into time intensity curves (TICs) for each voxel. The characteristics of these TICs provide important information about a lesion’s composition, but their analysis is time-consuming due to their large number. Subsequently, these TICs are used to classify a lesion as benign or malignant. This lesion scoring is commonly done manually by physicians and may therefore be subject to bias. We propose an approach that addresses both of these problems by combining an automated lesion classification with a visual confirmatory analysis, especially for uncertain cases. Firstly, we cluster the TICs of a lesion using ordering points to identify the clustering structure (OPTICS) and then visualize these clusters. Together with their relative size, they are added to a library. We then model fuzzy inference rules by using the lesion’s TIC clusters as antecedents and its score as consequent. Using a fuzzy scoring system, we can suggest a score for a new lesion. Secondly, to allow physicians to confirm the suggestion in uncertain cases, we display the TIC clusters together with their spatial distribution and allow them to compare two lesions side by side. With our knowledge-assisted comparative visual analysis, physicians can explore and classify breast lesions. The true positive prediction accuracy of our scoring system achieved 71.4% in one-fold cross-validation using 14 lesions.

Dentures are prosthetic devices replacing missing or damaged teeth, often used for dental reconstruction. Dental reconstruction improves the functional state and aesthetic appearance of teeth. State-of-the-art methods used by dental technicians typically do not include the aesthetic analysis, which often leads to unsatisfactory results for patients. In this paper, we present a virtual mirror approach for a dental treatment preview in augmented reality. Different denture presets are visually evaluated and compared by switching them on the fly. Our main goals are to provide a virtual dental treatment preview to facilitate early feedback, and hence to build the confidence and trust of patients in the outcome. The workflow of our algorithm is as follows. First, the face is detected and 2D facial landmarks are extracted. Then, 3D pose estimation of upper and lower jaws is performed and high-quality 3D models of the upper and lower dentures are fitted. The fitting uses the occlusal plane angle as determined mnually by dental technicians. To provide a realistic impression of the virtual teeth, the dentures are rendered with motion blur. We demonstrate the robustness and visual quality of our approach by comparing the results of a webcam to a DSLR camera under natural, as well as controlled lighting conditions., Vision, Modeling and Visualization, Augmented Reality, 29, 38, Aleksandr Amirkhanov, Artem Amirkhanov, Matthias Bernhard, Zsolt Toth, Sabine Stiller, Andreas Geier, Eduard Gröller, and Gabriel Mistelbauer, CCS Concepts: Computing methodologies --> Mixed / augmented reality; Applied computing --> Consumer healt

Blood vessels are well explored and researched in medicine and visualization. However, the investigation of vascular torsion has yet been unexplored. In order to understand the development and current state of a single blood vessel or even multiple connected ones, properties of vascular structures have to be analyzed. In this paper we assess the torsion of blood vessels in order to better understand their morphology. The aim of this work is to quantitatively gauge blood vessels by using an automated method that assumes an elliptical blood vessel model. This facilitates using state-of-the-art ellipse fitting algorithms from industrial measuring standards. In order to remove outliers, we propose a self-correcting iterative refitting of ellipses using neighboring information. The torsion information is visually conveyed by connecting the major and minor points of adjacent ellipses. Our final visualization comprises a visual representation of the blood vessel including four bands to outline the torsion., Eurographics Workshop on Visual Computing for Biology and Medicine, Cardiovascular, 129, 133, Gabriel Mistelbauer, Martin Zettwitz, Rüdiger Schernthaner, Dominik Fleischmann, Christian Teutsch, and Bernhard Preim, CCS Concepts: Computing methodologies --> Parametric curve and surface models; Shape analysis

Learning objectives Background Findings and procedure details Conclusion Personal information References, Learning objectives: In case of aortic dissections, several different measured parameters along the aorta (e.g., diameter, connecting arteries), or a combination of these, might be an indication for the risk for adverse events in the future. To study the predictive...

Learning objectives Background Findings and procedure details Conclusion Personal information References, Learning objectives: We demonstrate how advanced visualization of aortic diameter growth or evolution enhances the communication between radiologists and referring physicians with patients under aortic surveillance. Along a specific visualization plot we show how the...

Kardiovaskul��re Krankheiten treten immer h��ufiger in unserer Gesellschaft auf. Zu deren Diagnose werden spezielle Darstellungsmethoden ben��tigt, um z.B. den Blutfluss im Falle von luminalen Verschl��ssen zu untersuchen. Erm��glicht wird dies unter anderem durch die Technik der Curved Planar Reformation (CPR), welche longitudinale Schnitte entlang der Mittellinie von Blutgef����en erzeugt. Durch die M��glichkeit, um eine Achse zu rotieren, kann das gesamte Gef���� auf eventuell vorhandene vaskul��re Abnormit��ten untersucht werden (z.B. Verkalkungen an den Gef����w��nden, Stenosen und Verschl��sse). Wir pr��sentieren in dieser Arbeit eine Visualisierungstechnik namens Centerline Reformation (CR), welche es erlaubt, das Innere von Blutgef����en zu untersuchen, unabh��ngig von ihrer r��umlichen Orientierung. Ausgehend von den projizierten Mittellinien der Gef����e kann das Lumen jeder Ader durch Wellenausbreitung in der Bildebene erzeugt werden. Um die r��umlichen Distanzen in dichten Gef����systemen besser anzuzeigen, kann das Gef����lumen optional durch ein Halo abgegrenzt werden. Unsere Methode folgt dem Prinzip von Fokus und Kontext durch Anwendung verschiedener Darstellungsmethoden rund um das Lumen. Wir erl��utern, wie die korrekte Sichtbarkeit von mehreren sich ��berdeckenden Gef����en in der Bildebene gew��hrleistet werden kann. Dar��ber hinaus erm��glicht unsere Visualisierungstechnik die Untersuchung eines komplexen Gef����systems mittels interaktivem Ausw��hlen von Gef����en und nachfolgenden visuellen Abfragen. Eine verbesserte Version der Centerline Reformation (CR), welche ebenfalls in dieser Arbeit pr��sentiert wird, erm��glicht eine vollst��ndige dreidimensionale Reformation von Gef����strukturen mit Hilfe des Sehstrahlverfahrens. Wir bezeichnen diesen Prozess als Curved Surface Reformation (CSR). Bei dieser Methode breitet sich die Schnittfl��che nahtlos bis in das umliegende Gewebe der Blutgef����e aus. Zus��tzlich legen automatisch generierte Ausschnitte so viel wie m��glich des Gef����lumens frei, immer unter Gew��hrleistung der korrekten Sichtbarkeit. Diese Technik erm��glicht eine uneingeschr��nkte Navigation innerhalb des zu inspizierenden Gef����systems und erlaubt die Diagnose von allen tubul��ren Strukturen, unabh��ngig von deren r��umlicher Orientierung. Mit der immer gr����er werdenden Datenmenge wird von Seiten der Benutzer mehr Fachwissen ben��tigt, um die jeweils passende Darstellungsmethode f��r die Analyse der vorliegenden Daten auszuw��hlen. Wir pr��sentieren in dieser Arbeit einen Ansatz, der Expertenwissen in eine f��r Menschen einfach lesbare Form auslagert, und ein Inferenzsystem, das automatisch die f��r die jeweilige klinische Diagnose passende Darstellungsmethode bereitstellt. Die vorgestellte Methode tr��gt den Namen Smart Super Views. Die Ansichten der automatisch vorgeschlagenen Darstellungen werden aufgrund ihrer Relevanz, durch Anpassung ihrer Form und Gr����e, unterschiedlich kodiert. Mit Hilfe einer intelligenten r��umlichen Anordnung und Integration wird das Bild selbst zum Bildschirmmen��. Ein solches System bietet eine von Experten angeleitete medizinische Diagnose. Der vorgestellte Ansatz wird zuerst allgemein pr��sentiert, und dann durch Beschreibung eines konkreten Anwendungsfalles f��r die diagnostische Darstellung von Gef����en untermauert. Vaskul��re Strukturen bestehen ��blicherweise aus einer Vielzahl von Gef����en. Um diesem Umstand gerecht zu werden, beschreiben wir eine anatomische Anordnung zur Untersuchung des Gef����systems der menschlichen unteren Gliedma��en. Durch kreisf��rmige Aggregation der r��umlichen Information um die Mittellinien der Gef����e stellen wir ein einzelnes Bild f��r deren Untersuchung zur Verf��gung. Wir nennen diese Technik Curvicircular Feature Aggregation (CFA). Weiters wird eine Stabilit��tsanalyse ��ber lokale Abweichungen der Mittellinien von Gef����en er��rtert, welche es erm��glicht eventuelle ungenaue Definitionen zu lokalisieren. Durch die Pr��sentation dieser Information in der Darstellung ist eine schnelle visuelle Erfassung der Stabilit��t der Mittellinie realisierbar., Cardiovascular diseases occur with increasing frequency in our society. Their diagnosis often requires tailored visualization techniques, e.g., to examine the blood flow channel in case of luminal narrowing. Curved Planar Reformation (CPR) addresses this field by creating longitudinal sections along the centerline of blood vessels. With the possibility to rotate around an axis, the entire vessel can be assessed for possible vascular abnormalities (e.g., calcifications on the vessel wall, stenoses, and occlusions). In this thesis, we present a visualization technique, called Centerline Reformation (CR), that offers the possibility to investigate the interior of any blood vessel, regardless of its spatial orientation. Starting from the projected vessel centerlines, the lumen of any vessel is generated by employing wavefront propagation in image space. The vessel lumen can be optionally delineated by halos, to enhance spatial relationships when examining a dense vasculature. We present our method in a focus+context setup, by rendering a different kind of visualization around the lumen. We explain how to resolve correct visibility of multiple overlapping vessels in image space. Additionally, our visualization method allows the examination of a complex vasculature by means of interactive vessel filtering and subsequent visual querying. We propose an improved version of the Centerline Reformation (CR) technique, by generating a completely three-dimensional reformation of vascular structures using ray casting. We call this process Curved Surface Reformation (CSR). In this method, the cut surface is smoothly extended into the surrounding tissue of the blood vessels. Moreover, automatically generated cutaways reveal as much of the vessel lumen as possible, while still retaining correct visibility. This technique offers unrestricted navigation within the inspected vasculature and allows diagnosis of any tubular structure, regardless of its spatial orientation. The growing amount of data requires increasing knowledge from a user in order to select the appropriate visualization method for their analysis. In this thesis, we present an approach that externalizes the knowledge of domain experts in a human readable form and employs an inference system to provide only suitable visualization techniques for clinical diagnosis, namely Smart Super Views. We discuss the visual representation of such automatically suggested visualizations by encoding the respective relevance into shape and size of their view. By providing a smart spatial arrangement and integration, the image becomes the menu itself. Such a system offers a guided medical diagnosis by domain experts. After presenting the approach in a general setting, we describe an application scenario for diagnostic vascular visualization techniques. Since vascular structures usually consist of many vessels, we describe an anatomical layout for the investigation of the peripheral vasculature of the human lower extremities. By aggregating the volumetric information around the vessel centerlines in a circular fashion, we provide only a single static image for the assessment of the vessels. We call this method Curvicircular Feature Aggregation (CFA). In addition, we describe a stability analysis on the local deviations of the centerlines of vessels to determine potentially imprecise definitions. By conveying this information in the visualization, a fast visual analysis of the centerline stability is feasible.