@article{Schernthaner-2017-MCP, title = "Multipath Curved Planar Reformations of Peripheral CT Angiography: Diagnostic Accuracy and Time Efficiency", author = "Markus Schreiner and Hannes Platzgummer and Sylvia Unterhumer and Michael Weber and Gabriel Mistelbauer and Eduard Gr\"{o}ller and Christian Loewe and R\"{u}diger Schernthaner", year = "2018", abstract = "Objectives To compare diagnostic performance and time efficiency between 3D multipath curved planar reformations (mpCPRs) and axial images of CT angiography for the pre-interventional assessment of peripheral arterial disease (PAD), with digital subtraction angiography as the standard of reference. Methods Forty patients (10 females, mean age 72 years), referred to CTA prior to endovascular treatment of PAD, were prospectively included and underwent peripheral CT angiography. A semiautomated toolbox was used to render mpCPRs. Twenty-one arterial segments were defined in each leg; for each segment, the presence of stenosis[70% was assessed on mpCPRs and axial images by two readers, independently, with digital subtraction angiography as gold standard. Results Both readers reached lower sensitivity (Reader 1: 91 vs. 94%, p = 0.08; Reader 2: 89 vs. 93%, p = 0.03) but significantly higher specificity (Reader 1: 94 vs. 89%, p\0.01; Reader 2: 96 vs. 95%, p = 0.01) with mpCPRs than with axial images. Reader 1 achieved significantly higher accuracy with mpCPRs (93 vs. 91%, p = 0.02), and Reader 2 had similar overall accuracy in both evaluations (94 vs. 94%, p = 0.96). Both readers read mpCPRs significantly faster than axial images (Reader 1: 504500 based on mpCPRs vs. 704000 based on axial images; Reader 2: 404100 based on mpCPRs vs. 605700 based on axial images; p\0.01). Conclusions mpCPRs are a promising 3D reformation technique that facilitates a fast assessment of PAD with high diagnostic accuracy.", month = may, doi = "10.1007/s00270-017-1846-3", issn = "0174-1551", journal = "CardioVascular and Interventional Radiology", number = "5", volume = "41", pages = "718--725", keywords = "PAD, CTA, 3D reformation, mpCPRs", URL = "https://www.cg.tuwien.ac.at/research/publications/2018/Schernthaner-2017-MCP/", } @article{mindek-2017-dsn, title = "Data-Sensitive Visual Navigation", author = "Peter Mindek and Gabriel Mistelbauer and Eduard Gr\"{o}ller and Stefan Bruckner", year = "2017", abstract = "In visualization systems it is often the case that the changes of the input parameters are not proportional to the visual change of the generated output. In this paper, we propose a model for enabling data-sensitive navigation for user-interface elements. This model is applied to normalize the user input according to the visual change, and also to visually communicate this normalization. In this way, the exploration of heterogeneous data using common interaction elements can be performed in an efficient way. We apply our model to the field of medical visualization and present guided navigation tools for traversing vascular structures and for camera rotation around 3D volumes. The presented examples demonstrate that the model scales to user-interface elements where multiple parameters are set simultaneously.", month = oct, journal = "Computers & Graphics", volume = "67", number = "C", pages = "77--85", keywords = "navigation, exploration, medical visualization", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/mindek-2017-dsn/", } @article{miao_tvcg_2017, title = "Placenta Maps: In Utero Placental Health Assessment of the Human Fetus", author = "Haichao Miao and Gabriel Mistelbauer and Alexey Karimov and Amir Alansary and Alice Davidson and David F.A. Lloyd and Mellisa Damodaram and Lisa Story and Jana Hutter and Joseph V. Hajnal and Mary Rutherford and Bernhard Preim and Bernhard Kainz and Eduard Gr\"{o}ller", year = "2017", abstract = "null", journal = "IEEE Transactions on Visualization and Computer Graphics", volume = "23", number = "6", pages = "1612--1623", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/miao_tvcg_2017/", } @article{Mistelbauer_Gabriel_2016, title = "Aortic Dissection Maps: Comprehensive Visualization of Aortic Dissections for Risk Assessment", author = "Gabriel Mistelbauer and Johanna Schmidt and A.M. Sailer and Kathrin B\"{a}umler and Shannon Walters and Dominik Fleischmann", year = "2016", abstract = "Aortic dissection is a life threatening condition of the aorta, characterized by separation of its wall layers into a true and false lumen. A subset of patients require immediate surgical or endovascular repair. All survivors of the acute phase need long-term surveillance with imaging to monitor chronic degeneration and dilatation of the false lumen and prevent late adverse events such as rupture, or malperfusion. We introduce four novel plots displaying features of aortic dissections known or presumed to be associated with risk of future adverse events: Aortic diameter, the blood supply (outflow) to the aortic branches from the true and false lumen, the previous treatment, and an estimate of adverse event-free probabilities in one, two and 5 years. Aortic dissection maps, the composite visualization of these plots, provide a baseline for visual comparison of the complex features and associated risk of aortic dissection. These maps may lead to more individualized monitoring and improved, patient-centric treatment planning in the future.", month = sep, journal = "Eurographics Workshop on Visual Computing for Biology and Medicine (2016)", URL = "https://www.cg.tuwien.ac.at/research/publications/2016/Mistelbauer_Gabriel_2016/", } @techreport{karimov-2016-SD, title = "Statistics-Driven Localization of Dissimilarities in Data", author = "Alexey Karimov and Gabriel Mistelbauer and Thomas Auzinger and Eduard Gr\"{o}ller", year = "2016", abstract = "The identification of dissimilar regions in spatial and temporal data is a fundamental part of data exploration. This process takes place in applications, such as biomedical image processing as well as climatic data analysis. We propose a general solution for this task by employing well-founded statistical tools. From a large set of candidate regions, we derive an empirical distribution of the data and perform statistical hypothesis testing to obtain p-values as measures of dissimilarity. Having p-values, we quantify differences and rank regions on a global scale according to their dissimilarity to user-specified exemplar regions. We demonstrate our approach and its generality with two application scenarios, namely interactive exploration of climatic data and segmentation editing in the medical domain. In both cases our data exploration protocol unifies the interactive data analysis, guiding the user towards regions with the most relevant dissimilarity characteristics. The dissimilarity analysis results are conveyed with a radial tree, which prevents the user from searching exhaustively through all the data.", month = apr, number = "TR-186-2-16-1", address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", institution = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", note = "human contact: technical-report@cg.tuwien.ac.at", URL = "https://www.cg.tuwien.ac.at/research/publications/2016/karimov-2016-SD/", } @article{miao_2016_cgf, title = "Visual Quantification of the Circle of Willis: An Automated Identification and Standardized Representation", author = "Haichao Miao and Gabriel Mistelbauer and Christian Nasel and Eduard Gr\"{o}ller", year = "2016", abstract = "This paper presents a method for the visual quantification of cerebral arteries, known as the Circle of Willis (CoW). It is an arterial structure with the responsibility of supplying the brain with blood, however, dysfunctions can lead to strokes. The diagnosis of such a time-critical/urgent event depends on the expertise of radiologists and the applied software tools. They use basic display methods of the volumetric data without any support of advanced image processing and visualization techniques. The goal of this paper is to present an automated method for the standardized description of cerebral arteries in stroke patients in order to provide an overview of the CoW's configuration. This novel representation provides visual indications of problematic areas as well as straightforward comparisons between multiple patients. Additionally, we offer a pipeline for extracting the CoW from Time-of-Flight Magnetic Resonance Angiography (TOF-MRA) data sets together with an enumeration technique for labelling the arterial segments by detecting the main supplying arteries of the CoW. We evaluated the feasibility of our visual quantification approach in a study of 63 TOF-MRA data sets and compared our findings to those of three radiologists. The obtained results demonstrate that our proposed techniques are effective in detecting the arteries and visually capturing the overall configuration of the CoW.", issn = "1467-8659", journal = "Computer Graphics Forum", keywords = "Circle of Willis, medical visualization, information visualization", URL = "https://www.cg.tuwien.ac.at/research/publications/2016/miao_2016_cgf/", } @inproceedings{Miao_2015_VCBM, title = "CoWRadar: Visual Quantification of the Circle of Willis in Stroke Patients", author = "Haichao Miao and Gabriel Mistelbauer and Christian Nasel and Eduard Gr\"{o}ller", year = "2015", abstract = "This paper presents a method for the visual quantification of cerebral arteries, known as the Circle of Willis (CoW). The CoW is an arterial structure that is responsible for the brain’s blood supply. Dysfunctions of this arterial circle can lead to strokes. The diagnosis relies on the radiologist’s expertise and the software tools used. These tools consist of very basic display methods of the volumetric data without support of advanced technologies in medical image processing and visualization. The goal of this paper is to create an automated method for the standardized description of cerebral arteries in stroke patients in order to provide an overview of the CoW’s configuration. This novel display provides visual indications of problematic areas as well as straightforward comparisons between multiple patients. Additionally, we offer a pipeline for extracting the CoW from Time-of-Flight Magnetic Resonance Angiography (TOF-MRA) data sets. An enumeration technique for the labeling of the arterial segments is therefore suggested. We also propose a method for detecting the CoW’s main supplying arteries by analyzing the coronal, sagittal and transverse image planes of the data sets. We evaluated the feasibility of our visual quantification approach in a study of 63 TOF-MRA data sets and compared our findings to those of three radiologists. The obtained results demonstrate that our proposed techniques are effective in detecting the arteries of the CoW.", month = sep, isbn = "978-3-905674-82-8", publisher = "The Eurographics Association", organization = "EG Digital Library", location = "Chester, United Kingdom", issn = "2070-5786", editor = "Katja B\"{u}hler and Lars Linsen and Nigel W. John", booktitle = "EG Workshop on Visual Computing for Biology and Medicine", pages = "1--10", URL = "https://www.cg.tuwien.ac.at/research/publications/2015/Miao_2015_VCBM/", } @article{Mistelbauer_Gabriel_2015_NHR, title = "New hybrid reformations of peripheral CT angiography: do we still need axial images?", author = "R\"{u}diger Schernthaner and Florian Wolf and Gabriel Mistelbauer and Michael Weber and Milo\v{s} \v{S}r\'{a}mek and Eduard Gr\"{o}ller and Christian Loewe", year = "2015", abstract = "Purpose To quantify the detectability of peripheral artery stenosis on hybrid CT angiography (CTA) reformations. Methods Hybrid reformations were developed by combining multipath curved planar reformations (mpCPR) and maximum intensity projections (MIP). Fifty peripheral CTAs were evaluated twice: either with MIP, mpCPR and axial images or with hybrid reformations only. Digital subtraction angiography served as gold standard. Results Using hybrid reformations, two independent readers detected 88.0% and 81.3% of significant stenosis, respectively. However, CTA including axial images detected statistically significant more lesions (98%). Conclusion Peripheral CTA reading including axial images is still recommended. Further improvement of these hybrid reformations is necessary.", month = jul, journal = "Clinic Imaging", number = "4", volume = "39", pages = "603--607", keywords = "Peripheral arterial occlusive disease;, CT angiography;, Three-dimensional reformations;, Postprocessing", URL = "https://www.cg.tuwien.ac.at/research/publications/2015/Mistelbauer_Gabriel_2015_NHR/", } @article{karimov-2015-HD, title = "Guided Volume Editing based on Histogram Dissimilarity", author = "Alexey Karimov and Gabriel Mistelbauer and Thomas Auzinger and Stefan Bruckner", year = "2015", abstract = "Segmentation of volumetric data is an important part of many analysis pipelines, but frequently requires manual inspection and correction. While plenty of volume editing techniques exist, it remains cumbersome and error-prone for the user to find and select appropriate regions for editing. We propose an approach to improve volume editing by detecting potential segmentation defects while considering the underlying structure of the object of interest. Our method is based on a novel histogram dissimilarity measure between individual regions, derived from structural information extracted from the initial segmentation. Based on this information, our interactive system guides the user towards potential defects, provides integrated tools for their inspection, and automatically generates suggestions for their resolution. We demonstrate that our approach can reduce interaction effort and supports the user in a comprehensive investigation for high-quality segmentations. ", month = may, journal = "Computer Graphics Forum", volume = "34", number = "3", pages = "91--100", keywords = "Edge and feature detection, Image Processing and Computer Vision, Computer Graphics, Display algorithms, Picture/Image Generation, Segmentation, Methodology and Techniques, Interaction techniques", URL = "https://www.cg.tuwien.ac.at/research/publications/2015/karimov-2015-HD/", } @talk{mistelbauer-2015-abvv, title = "Advanced Blood Vessel Visualization", author = "Gabriel Mistelbauer", year = "2015", abstract = "Visualizations of vascular structures are frequently used in radiological investigations to detect and analyze vascular diseases. Thus, the analysis of blood vessels for their diagnosis and treatment are important research fields of radiology. Angiographic interventions, such as stenting, balloon dilatation, or bypass surgery, need to be planned with care and precision, due to their major impact on the patient’s health state. In order to optimally decide on the therapeutic procedure, specific diagnostic methods are required. They assess the health state of blood vessels and answer clinically relevant questions such as, e.g., if blood is partially or entirely hindered from flowing through a vessel by a clot or a mineral deposition on the vessel wall, such as a calcification. In this talk, I will present Curved Planar Reformation (CPR), a method that is designed for the investigation of peripheral arteries. This technique creates a curved plane along the centerlines of blood vessels, revealing their interior, or lumen. This allows radiologists to precisely judge if blood is able to flow through a vessel or if it is significantly hindered, as in the case of a stenosis. I will also introduce advanced methods, like Curved Surface Reformation (CSR), which computes the vessel lumen entirely in 3D, offering high-quality interactive visualizations of the vessels' interior. While it is possible with conventional CPR methods to examine the whole vessel lumen by rotating around the centerline of a vessel, I will present other possibilities of visualizing vascular structures, such as Curvicircular Feature Aggregation (CFA). This approach aggregates the single rotated images of CPR into a single view. By eliminating the need for rotation, blood vessels can be investigated by inspecting only one image. This method can be used as a guidance and visual analysis tool for treatment planning. As vessel visualization provides very specific insight, the overall contextual information outside the vessel lumen might deteriorate. I will present means how to overcome this by providing a spatial indication. Advancing to visualization of the cerebral arteries, I will present an approach how to automatically extract the Circle of Willis and assess the morphology of this arterial circle within a single visualization. Despite being an important part of many analysis pipelines, the segmentation of blood vessels commonly requires manual inspection and correction. While plenty of volume editing techniques exist, it remains cumbersome and error-prone for the user to find and select appropriate regions for editing. In this talk, I will present the application of a general volume editing technique to the domain of vascular structures and how it reduces the necessary interaction to obtain high-quality segmentations. Due to the ever growing volume of acquired data and information, users have to be constantly aware of the methods for their exploration and for interaction. Owing to this, innovations may be used inappropriately and users may become skeptical. In this talk, I will present a knowledge-assisted interface for medical visualization, which reduces the necessary effort to use new visualization methods, by providing only the most relevant ones in a smart way. Consequently, we are able to expand such a system with innovations without the users to worry about when, where, and especially how they may or should use them. I will show how to apply this concept in the context of blood vessels investigations.", event = "Invited Talk", location = "Otto-von-Guericke University Magdeburg, Germany", URL = "https://www.cg.tuwien.ac.at/research/publications/2015/mistelbauer-2015-abvv/", } @misc{fmistelbauer-2014-adict, title = "ActiveDICOM - Enhancing Static Medical Images with Interaction", author = "Florian Mistelbauer and Gabriel Mistelbauer and Eduard Gr\"{o}ller", year = "2014", abstract = "Digital Imaging and Communications in Medicine (DICOM) is a well-establish standard in medical imaging, consisting not only of image data, but sensitive data such as patient and examination information. Nowadays, although having a large variety of advanced rendering techniques available, DICOM images are still generated and sent to the Picture Archiving and Communication System (PACS). These images are then fetched by the medical doctor from a workstation and used for medical reporting. The user has no other possibilities than being able to change the windowing function for displaying the DICOM images. If a certain region is of special interest, either images of the whole data set are generated or have to be specifically requested. Both approaches consume a considerable amount of time. Secondly, the image generation on demand remains pending until done by the responsible assistant. Despite supporting a broad range of features and being widely applied, DICOM images remain static. We propose a visualization mapping language, Active DICOM Script (ADICT), which enhances conventional DICOM with interactive elements by combining heterogeneous data, interaction and visualization. Such DICOM images are then called Active Digital Imaging and Communications in Medicine (ActiveDICOM).", month = sep, series = "EG VCBM 2014", location = "Vienna, Austria", event = "Eurographics Workshop on Visual Computing for Biology and Medicine", booktitle = "Posters at Eurographics Workshop on Visual Computing for Biology and Medicine", Conference date = "Poster presented at Eurographics Workshop on Visual Computing for Biology and Medicine (2014-09-03--2014-09-05)", URL = "https://www.cg.tuwien.ac.at/research/publications/2014/fmistelbauer-2014-adict/", } @talk{mistelbauer-2014-ekc, title = "Advanced Vessel Visualization", author = "Gabriel Mistelbauer", year = "2014", event = "EU-Korea Conference on Science and Technology", location = "Vienna, Austria", URL = "https://www.cg.tuwien.ac.at/research/publications/2014/mistelbauer-2014-ekc/", } @article{Auzinger_Mistelbauer_2013_CSR, title = "Vessel Visualization using Curved Surface Reformation", author = "Thomas Auzinger and Gabriel Mistelbauer and Ivan Baclija and R\"{u}diger Schernthaner and Arnold K\"{o}chl and Michael Wimmer and Eduard Gr\"{o}ller and Stefan Bruckner", year = "2013", abstract = "Visualizations of vascular structures are frequently used in radiological investigations to detect and analyze vascular diseases. Obstructions of the blood flow through a vessel are one of the main interests of physicians, and several methods have been proposed to aid the visual assessment of calcifications on vessel walls. Curved Planar Reformation (CPR) is a wide-spread method that is designed for peripheral arteries which exhibit one dominant direction. To analyze the lumen of arbitrarily oriented vessels, Centerline Reformation (CR) has been proposed. Both methods project the vascular structures into 2D image space in order to reconstruct the vessel lumen. In this paper, we propose Curved Surface Reformation (CSR), a technique that computes the vessel lumen fully in 3D. This offers high-quality interactive visualizations of vessel lumina and does not suffer from problems of earlier methods such as ambiguous visibility cues or premature discretization of centerline data. Our method maintains exact visibility information until the final query of the 3D lumina data. We also present feedback from several domain experts.", month = dec, journal = "IEEE Transactions on Visualization and Computer Graphics (Proceedings of IEEE Scientific Visualization 2013)", volume = "19", number = "12", pages = "2858--2867", keywords = "Surface Approximation, Vessel, Reformation, Volume Rendering", URL = "https://www.cg.tuwien.ac.at/research/publications/2013/Auzinger_Mistelbauer_2013_CSR/", } @phdthesis{mistelbauer_2013_SIV, title = "Smart Interactive Vessel Visualization in Radiology ", author = "Gabriel Mistelbauer", year = "2013", abstract = "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. ", month = nov, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2013/mistelbauer_2013_SIV/", } @article{karimov-2013-vivisection, title = "ViviSection: Skeleton-based Volume Editing", author = "Alexey Karimov and Gabriel Mistelbauer and Johanna Schmidt and Peter Mindek and Elisabeth Schmidt and Timur Sharipov and Stefan Bruckner and Eduard Gr\"{o}ller", year = "2013", abstract = "Volume segmentation is important in many applications, particularly in the medical domain. Most segmentation techniques, however, work fully automatically only in very restricted scenarios and cumbersome manual editing of the results is a common task. In this paper, we introduce a novel approach for the editing of segmentation results. Our method exploits structural features of the segmented object to enable intuitive and robust correction and verification. We demonstrate that our new approach can significantly increase the segmentation quality even in difficult cases such as in the presence of severe pathologies.", month = jun, journal = "Computer Graphics Forum", volume = "32", number = "3", pages = "461--470", URL = "https://www.cg.tuwien.ac.at/research/publications/2013/karimov-2013-vivisection/", } @article{mistelbauer-2013-cfa, title = "Vessel Visualization using Curvicircular Feature Aggregation", author = "Gabriel Mistelbauer and Anca Morar and Andrej Varchola and R\"{u}diger Schernthaner and Ivan Baclija and Arnold K\"{o}chl and Armin Kanitsar and Stefan Bruckner and Eduard Gr\"{o}ller", year = "2013", abstract = "Radiological investigations are common medical practice for the diagnosis of peripheral vascular diseases. Existing visualization methods such as Curved Planar Reformation (CPR) depict calcifications on vessel walls to determine if blood is still able to flow. While it is possible with conventional CPR methods to examine the whole vessel lumen by rotating around the centerline of a vessel, we propose Curvicircular Feature Aggregation (CFA), which aggregates these rotated images into a single view. By eliminating the need for rotation, vessels can be investigated by inspecting only one image. This method can be used as a guidance and visual analysis tool for treatment planning. We present applications of this technique in the medical domain and give feedback from radiologists.", month = jun, journal = "Computer Graphics Forum", volume = "32", number = "3", pages = "231--240", URL = "https://www.cg.tuwien.ac.at/research/publications/2013/mistelbauer-2013-cfa/", } @inproceedings{mistelbauer-2012-ssv, title = "Smart Super Views - A Knowledge-Assisted Interface for Medical Visualization", author = "Gabriel Mistelbauer and Hamed Bouzari and R\"{u}diger Schernthaner and Ivan Baclija and Arnold K\"{o}chl and Stefan Bruckner and Milo\v{s} \v{S}r\'{a}mek and Eduard Gr\"{o}ller", year = "2012", abstract = "Due to the ever growing volume of acquired data and information, users have to be constantly aware of the methods for their exploration and for interaction. Of these, not each might be applicable to the data at hand or might reveal the desired result. Owing to this, innovations may be used inappropriately and users may become skeptical. In this paper we propose a knowledge-assisted interface for medical visualization, which reduces the necessary effort to use new visualization methods, by providing only the most relevant ones in a smart way. Consequently, we are able to expand such a system with innovations without the users to worry about when, where, and especially how they may or should use them. We present an application of our system in the medical domain and give qualitative feedback from domain experts.", month = oct, publisher = "IEEE Computer Society", location = "Seattle, WA, USA", booktitle = "IEEE Conference on Visual Analytics Science and Technology (IEEE VAST) 2012", pages = "163--172", URL = "https://www.cg.tuwien.ac.at/research/publications/2012/mistelbauer-2012-ssv/", } @inproceedings{mistelbauer-2012-cr, title = "Centerline Reformations of Complex Vascular Structures", author = "Gabriel Mistelbauer and Andrej Varchola and Hamed Bouzari and Juraj Starinsky and Arnold K\"{o}chl and R\"{u}diger Schernthaner and Dominik Fleischmann and Eduard Gr\"{o}ller and Milo\v{s} \v{S}r\'{a}mek", year = "2012", abstract = "Visualization of vascular structures is a common and frequently performed task in the field of medical imaging. There exist well established and applicable methods such as Maximum Intensity Projection (MIP) and Curved Planar Reformation (CPR). However, when calcified vessel walls are investigated, occlusion hinders exploration of the vessel interior with MIP. In contrast, CPR offers the possibility to visualize the vessel lumen by cutting a single vessel along its centerline. Extending the idea of CPR, we propose a novel technique, called Centerline Reformation (CR), which is capable of visualizing the lumen of spatially arbitrarily oriented vessels not necessarily connected in a tree structure. In order to visually emphasize depth, overlap and occlusion, halos can optionally envelope the vessel lumen. The required vessel centerlines are obtained from volumetric data by performing a scale-space based feature extraction. We present the application of the proposed technique in a focus and context setup. Further, we demonstrate how it facilitates the investigation of dense vascular structures, particularly cervical vessels or vessel data featuring peripheral arterial occlusive diseases or pulmonary embolisms. Finally, feedback from domain experts is given.", isbn = "978-1-4673-0863-2", location = "Songdo, Korea (South) ", booktitle = "Pacific Visualization Symposium (PacificVis), 2012 IEEE", pages = "233--240", URL = "https://www.cg.tuwien.ac.at/research/publications/2012/mistelbauer-2012-cr/", } @mastersthesis{mistelbauer-2010-pvv, title = "Automated Processing and Visualization of Vessel Trees", author = "Gabriel Mistelbauer", year = "2010", abstract = "Automated processing and visualization of vascular structures is a common task in medical imaging. Maximum Intensity Projection (MIP) and Curved Planar Reformation (CPR) are well established and robust methods for clinical use. In case of calcified vessel walls, occlusion prevents exploring the inside of the vessels when using MIP. CPR allows to cut a single vessel along its centerline and to visualize the lumen. Extending the idea of CPR, a novel automatic method for vessel visualization is proposed. It works with multiple vessel centerlines that do not necessarily need to be connected into a tree structure. Arbitrarily complex vascular structures are rendered in the volume as point sets and optionally, occlusion halos are created around them to enhance depth perception. Vessel centerlines are automatically extracted from a volumetric data-set after performing feature extraction in a scale-space. The user is provided with the ability to control the final image and he or she can visually select the desired centerlines with visual queries by stroking with the mouse. Furthermore, a combination with the recent Maximum Intensity Difference Accumulation (MIDA) visualization technique is presented, which has the advantages of Direct Volume Rendering (DVR) such as occlusion and depth cues, but does not require an explicit transfer function specification. It is demonstrated how the proposed technique can be applied to large data-sets, particularly to data featuring peripheral arterial occlusive diseases or in order to detect possible embolisms as presented on a pulmonary data-set.", month = jul, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2010/mistelbauer-2010-pvv/", } @xmascard{xmas-2010, title = "X-Mas 2010", author = "Gabriel Mistelbauer", year = "2010", abstract = "“Mirror mirror on the wall who is the master of them all?!” The background of this card is a flow visualization of a hurricane data-set, which is rendered using Line Integral Convolution. The pulmonary and the human lower extremity data-sets are rendered with Maximum Intensity Projection in the AngioVis Toolbox. The vessels have been detected using multi-scale analysis. “Spieglein Spieglein an der Wand wer ist der Meister im ganzen Land?!” Der Hintergrund dieser Karte ist eine Str\"{o}mungsvisualisierung von einem Hurricane Datensatz, welcher mit Hilfe von Line Integral Convolution dargestellt wird. Die Datens\"{a}tze einer Lunge und die der Beine eines Menschen werden im AngioVis Programm mittels Maximum Intensity Projection gerendert. Die Adern sind mittels Multi-scale Analysis detektiert worden.", URL = "https://www.cg.tuwien.ac.at/research/publications/2010/xmas-2010/", }