Patient-Specific Mappings between Myocardial and Coronary Anatomy

The segmentation of the myocardium based on the 17-segment model as recommended by the American Heart Association is widely used in medical practice. The patient-specific coronary anatomy does not play a role in this model. Due to large variations in coronary anatomy among patients, this can result in an inaccurate mapping between myocardial segments and coronary arteries. We present two approaches to include the patient-specific coronary anatomy in this mapping. The first approach adapts the 17-segment model to fit the patient. The second approach generates a less constrained mapping that does not necessarily conform to this model. Both approaches are based on a Voronoi diagram computation of the primary coronary arteries using geodesic distances along the epicardium in three-dimensional space. We demonstrate both our approaches with several patients and show how our first approach can also be used to fit volume data to the 17-segment model. Our technique gives detailed insight into the coronary anatomy in a single diagram. Based on the feedback provided by clinical experts we conclude that it has the potential to provide a more accurate relation between deficiencies in the myocardium and the supplying coronary arteries

Comprehensive visualization of cardiac MRI data

Zsfassung in dt. SpracheKoronare Herzkrankheit ist eine der führenden Todesursachen in der westlichen Welt. Die kontinuierliche Verbesserung der Magnetresonanztomographie (MRT) erleichtert genauere Diagnosen, indem sie immer detailliertere Informationen über die Lebensfähigkeit, das Funktionieren, die Durchblutung und die Anatomie des Herzens eines Patienten liefert.Diese zunehmende Menge an Informationen schafft die Notwendigkeit für effizientere und effektivere Mittel der Verarbeitung dieser Daten.Diese Dissertation präsentiert mehrere neue Techniken, die eine umfassendere Visualisierung des Patienten bei der Diagnose von Erkrankungen der Herzkranzgefäße mittels MRT unterstützen. Das volumetrische Polardiagram wird als Erweiterung des Polardiagrams, welches eine bestehende Visualusierungstechnik in der klinischen Praxis ist, eingeführt. Dieses neuartige Konzept bietet eine umfassendere Sicht auf die Lebensfähigkeit des Herzens eines Patienten, indem detaillierte Informationen über die Transmuralität der Narbe ohne Diskontinuitäten bereitgestellt werden.Anatomische Zusammenhänge gehen in abstrakten Darstellungen von Daten häufig verloren. Darüberhinaus liefern einige Arten von Scans relativ wenig anatomischen Kontext. Mehrere Techniken zur Wiederherstellung des anatomischen Bezugs werden vorgestellt. Die primären Koronararterien sind in einem Scan des ganzen Herzens segmentiert und werden auf ein volumetrisches Polardiagram abgebildet. Hierbei wird der abstrakten Repräsentation anatomischer Kontext hinzugefügt. Ebenso, werden segmentierte späte Anreicherungs Daten zusammen mit einer drei-dimensionalen Segmentierung des patientenspezifischen Herzmuskels und koronarer Anatomie dargestellt. Darüberhinaus werden koronare Versorgungsgebiete aus den patientenspezifischen Daten berechnet. Dies bedeutet eine Verbesserung gegenüber Modellen welche auf Bevölkerungsdurchschnitten basieren.Informationen über die Durchblutung des Herzmuskels welche aus MRT-Aufnahmen abgeleitet werden können sind in der Regel von relativ geringer Auflösung. Unter Verwendung hochauflösender anatomischen Daten wird ein Konzept für die Visualisierung simulierter Durchblutung des Herzmuskels präsentiert. Dabei wird die detaillierte Information über die Durchblutung genutzt. Schließlich, wird eine wirklich umfassende Visualisierung einer Herz-MRT-Untersuchung erforscht. Dabei werden Scans des ganzen Herzens, der Herzvitalität, der Herzfunktion und der Durchblutung in einer einzigen Visualisierung kombiniert. Die eingeführten Konzepte fördern den Aufbau eines umfassenderen Überblicks über den Patienten. Die dabei zusätzlich gewonnene Information kann für den Diagnoseprozess von Nutzem sein.Coronary artery disease is one of the leading causes of death in the western world. The continuous improvements in magnetic resonance imaging technology facilitate more accurate diagnoses by providing increasingly more detailed information on the viability, functioning, perfusion, and anatomy of a patient's heart. This increasing amount of information creates the need for more efficient and more effective means of processing these data.This thesis presents several novel techniques that facilitate a more comprehensive visualization of a patient's heart to assist in the diagnosis of coronary artery disease using magnetic resonance imaging (MRI). The volumetric bull's eye plot is introduced as an extension of an existing visualization technique used in clinical practice-the bull's eye plot.This novel concept offers a more comprehensive view on the viability of a patient's heart by providing detailed information on the transmurality of scar while not suffering from discontinuities.Anatomical context is often lost due to abstract representations of data, or may be scarce due to the nature of the scanning protocol. Several techniques to restore the relation to anatomy are presented. The primary coronary arteries are segmented in a whole heart scan and mapped onto a volumetric bull's eye plot, adding anatomical context to an abstract representation. Similarly, segmented late enhancement data are rendered along with a three-dimensional segmentation of the patient-specific myocardial and coronary anatomy. Additionally, coronary supply territories are computed from patient-specific data as an improvement over models based on population averages.Information on the perfusion of the myocardium provided by MRI is typically of fairly low resolution. Using high-resolution anatomical data, an approach to visualize simulated myocardial perfusion is presented, taking full advantage of the detailed information on perfusion. Finally, a truly comprehensive visualization of a cardiac MRI exam is explored by combining whole heart, late enhancement, functional, and perfusion scans in a single visualization. The concepts introduced help to build a more comprehensive view of the patient and the additional information may prove to be beneficial for the diagnostic process.12

Spegling av barns identitet. Pedagogers syn på hur de i samspel påverkar barns identitetsskapande

We present MetricView, a software visualization and exploration tool that combines traditional UML diagram visualization with metric visualization in an effective way. MetricView is very easy and natural to use for software architects and developers yet offers a powerful set of mechanisms that allow fine customization of the visualizations for getting specific insights. We discuss several visual and architectural design choices which turned out to be important in the construction of MetricView, and illustrate our approach with several results using real-life datasets.

Visualization of voxel data

\u3cp\u3eThe invention relates to visualization of medical images, and in embodiments to the visualization of the left ventricle of the human heart or other organs. A method of visualizing one or more sets of voxel data is disclosed. The method comprising: providing one or more sets of voxel data, providing and segmenting the voxel data in accordance with a segment model. The segmented voxel data is reformatted to fit a reference shape (20) being defined by at least an inner (22) reference surface and an outer (23) reference surface. The reformatted voxel data is mapped to a target shape being defined by at least a first (29) target surface and a second (200) target surface. The target shape is moreover visualized. The mapping of the reformatted voxel data to a target shape is a mapping of one or more property values from the inner reference surface to the first target surface, and from the outer reference surface to the second target surface, and where a direction (26, 27) extending along the inter-surface distance of the reference shape is maintained in the target shape.\u3c/p\u3