Surface Registration for Pharyngeal Radiation Treatment Planning

Endoscopy is an in-body examination procedure that enables direct visualization of tumor spread on tissue surfaces. In the context of radiation treatment planning for throat cancer, there have been attempts to fuse this endoscopic information into the planning CT space for better tumor localization. One way to achieve this CT/Endoscope fusion is to first reconstruct a full 3D surface model from the endoscopic video and then register that surface into the CT space. These two steps both require an algorithm that can accurately register two or more surfaces. In this dissertation, I present a surface registration method I have developed, called Thin Shell Demons (TSD), for achieving the two goals mentioned above. There are two key aspects in TSD: geometry and mechanics. First, I develop a novel surface geometric feature descriptor based on multi-scale curvatures that can accurately capture local shape information. I show that the descriptor can be effectively used in TSD and other surface registration frameworks, such as spectral graph matching. Second, I adopt a physical thin shell model in TSD to produce realistic surface deformation in the registration process. I also extend this physical model for orthotropic thin shells and propose a probabilistic framework to learn orthotropic stiffness parameters from a group of known deformations. The anisotropic stiffness learning opens up a new perspective to shape analysis and allows more accurate surface deformation and registration in the TSD framework. Finally, I show that TSD can also be extended into a novel groupwise registration framework. The advantages of Thin Shell Demons allow us to build a complete 3D model of the throat, called an endoscopogram, from a group of single-frame-based reconstructions. It also allows us to register an endoscopogram to a CT segmentation surface, thereby allowing information transfer for treatment planning.Doctor of Philosoph

Rapid development of applications for the interactive visual analysis of multimodal medical data

Multimodale medizinische Volumendaten gewinnen zunehmend an Verbreitung. Wir diskutieren verschiedene interaktive Applikationen welche den Nutzer bei der Analyse dieser Daten unterstützen. Alle Applikationen basieren auf Erweiterungen des Voreen Frameworks, welche ebenfalls in dieser Dissertation diskutiert werden. With multimodal volumetric medical data sets becoming more common due to the increasing availability of scanning hardware, software for the visualization and analysis of such data sets needs to become more efficient as well in order to prevent overloading the user with data. This dissertation presents several interactive techniques for the visual analysis of medical volume data. All applications are based on extensions to the Voreen volume rendering framework, which we will discuss first. Since visual analysis applications are interactive by definition, we propose a general-purpose navigation technique for volume data. Next, we discuss our concepts for the interactive planning of brain tumor resections. Finally, we present two systems designed to work with images of vasculature. First, we discuss an interactive vessel segmentation system enabling an efficient, visually supported workflow. Second, we propose an application for the visual analysis of PET tracer uptake along vessels

Principles and Practice of Case-based Clinical Reasoning Education: A Method for Preclinical Students

This volume describes and explains the educational method of Case-Based Clinical Reasoning (CBCR) used successfully in medical schools to prepare students to think like doctors before they enter the clinical arena and become engaged in patient care. Although this approach poses the paradoxical problem of a lack of clinical experience that is so essential for building proficiency in clinical reasoning, CBCR is built on the premise that solving clinical problems involves the ability to reason about disease processes. This requires knowledge of anatomy and the working and pathology of organ systems, as well as the ability to regard patient problems as patterns and compare them with instances of illness scripts of patients the clinician has seen in the past and stored in memory. CBCR stimulates the development of early, rudimentary illness scripts through elaboration and systematic discussion of the courses of action from the initial presentation of the patient to the final steps of clinical management. The book combines general backgrounds of clinical reasoning education and assessment with a detailed elaboration of the CBCR method for application in any medical curriculum, either as a mandatory or as an elective course. It consists of three parts: a general introduction to clinical reasoning education, application of the CBCR method, and cases that can used by educators to try out this method

Automatic Segmentation of the Mandible for Three-Dimensional Virtual Surgical Planning

Three-dimensional (3D) medical imaging techniques have a fundamental role in the field of oral and maxillofacial surgery (OMFS). 3D images are used to guide diagnosis, assess the severity of disease, for pre-operative planning, per-operative guidance and virtual surgical planning (VSP). In the field of oral cancer, where surgical resection requiring the partial removal of the mandible is a common treatment, resection surgery is often based on 3D VSP to accurately design a resection plan around tumor margins. In orthognathic surgery and dental implant surgery, 3D VSP is also extensively used to precisely guide mandibular surgery. Image segmentation from the radiography images of the head and neck, which is a process to create a 3D volume of the target tissue, is a useful tool to visualize the mandible and quantify geometric parameters. Studies have shown that 3D VSP requires accurate segmentation of the mandible, which is currently performed by medical technicians. Mandible segmentation was usually done manually, which is a time-consuming and poorly reproducible process. This thesis presents four algorithms for mandible segmentation from CT and CBCT and contributes to some novel ideas for the development of automatic mandible segmentation for 3D VSP. We implement the segmentation approaches on head and neck CT/CBCT datasets and then evaluate the performance. Experimental results show that our proposed approaches for mandible segmentation in CT/CBCT datasets exhibit high accuracy

Feature extraction to aid disease detection and assessment of disease progression in CT and MR colonography

Computed tomographic colonography (CTC) is a technique employed to examine the whole colon for cancers and premalignant adenomas (polyps). Oral preparation is taken to fully cleanse the colon, and gas insufflation maximises the attenuation contrast between the enoluminal colon surface and the lumen. The procedure is performed routinely with the patient both prone and supine to redistribute gas and residue. This helps to differentiate fixed colonic pathology from mobile faecal residue and also helps discover pathology occluded by retained fluid or luminal collapse. Matching corresponding endoluminal surface locations with the patient in the prone and supine positions is therefore an essential aspect of interpretation by radiologists; however, interpretation can be difficult and time consuming due to the considerable colonic deformations that occur during repositioning. Hence, a method for automated registration has the potential to improve efficiency and diagnostic accuracy. I propose a novel method to establish correspondence between prone and supine CT colonography acquisitions automatically. The problem is first simplified by detecting haustral folds which are elongated ridgelike endoluminal structures and can be identified by curvature based measurements. These are subsequently matched using appearance based features, and their relative geometric relationships. It is shown that these matches can be used to find correspondence along the full length of the colon, but may also be used in conjunction with other registration methods to achieve a more robust and accurate result, explicitly addressing the problem of colonic collapse. The potential clinical value of this method has been assessed in an external clinical validation, and the application to follow-up CTC surveillance has been investigated. MRI has recently been applied as a tool to quantitatively evaluate the therapeutic response to therapy in patients with Crohn's disease, and is the preferred choice for repeated imaging. A primary biomarker for this evaluation is the measurement of variations of bowel wall thickness on changing from the active phase of the disease to remission; however, a poor level of interobserver agreement of measured thickness is reported and therefore a system for accurate, robust and reproducible measurements is desirable. I propose a novel method which will automatically track sections of colon, by estimating the positions of elliptical cross sections. Subsequently, estimation of the positions of the inner and outer bowel walls are made based on image gradient information and therefore a thickness measurement value can be extracted

The Impact of Debriefing for Meaningful Learning on Knowledge Development, Knowledge Retention, and Knowledge Application Among Baccalaureate Nursing Students

Debriefing offers an opportunity to ensure that students can master critical components of nursing that they might not otherwise learn and to remove epistemological roadblocks to knowledge acquisition. Within this study, Debriefing for Meaningful Learning (DML), a theoretically-derived, evidence based and structured debriefing method, was used to explore student’s knowledge acquisition, knowledge retention, and application of knowledge from one patient situation to a different, yet parallel, situation. This quasi-experimental pretest, posttest study explored the impact of the type of debriefing method on the development of knowledge, knowledge retention, and knowledge application. Eighty-two prelicensure baccalaureate nursing students, enrolled in an adult health (medical-surgical nursing) theory course, participated in this study testing the use of Debriefing for Meaningful Learning compared with customary debriefing. The outcomes of this study revealed a significant difference in knowledge acquisition, knowledge retention, and knowledge application with DML compared to customary debriefing. These findings are significant for nurse educators using simulation to potentiate clinical learning in prelicensure students and add to the growing evidence regarding the impact of debriefing

Principles and Practice of Case-based Clinical Reasoning Education: A Method for Preclinical Students

assessment of clinical reasoning; diagnostic bias; diagnostic errors; dual process theory; scripts; medical problem-solving; peer teaching; problem-based learning; semantic qualifier

Annals of Scientific Society for Assembly, Handling and Industrial Robotics

This Open Access proceedings present a good overview of the current research landscape of industrial robots. The objective of MHI Colloquium is a successful networking at academic and management level. Thereby the colloquium is focussing on a high level academic exchange to distribute the obtained research results, determine synergetic effects and trends, connect the actors personally and in conclusion strengthen the research field as well as the MHI community. Additionally there is the possibility to become acquainted with the organizing institute. Primary audience are members of the scientific association for assembly, handling and industrial robots (WG MHI)

The Humid Condition

The Humid Condition: (More) Overheated Observations continues on the clicking heels of Dominic Pettman’s Humid, All Too Humid (2016), providing a companion volume of pithy and witty observations for our overheated age. Covering topics from pop culture to academia to romance to politics to human mortality to everything in between, this collection of pointed musings aims to amuse, edify, instruct, provoke, tease, caution, and inspire. As with the first installment, the spirit of this book represents a fusion of Montaigne and Wilde; a mashup of Adorno and Yogi Berra; a parallel channeling of Marx and Marx (both Karl and Groucho). No doubt, Hannah Arendt would be appalled at the irreverence on display within these pages. Then again, “Heidegger has left the bildung.” And as the author himself notes: “I have nothing new to say. And I’m saying it!