Proc. SPIE. 9789, Medical Imaging 2016: PACS and Imaging Informatics: Next Generation and Innovations
KEYWORDS: Data modeling, Data modeling, Surgery, Data storage, Image segmentation, Medical imaging, Data archive systems, Cognition, Neuroimaging, Data integration, Knowledge acquisition, Information science, Standards development, Knowledge management, Imaging informatics, Picture Archiving and Communication System
In the surgical domain, individual clinical experience, which is derived in large part from past clinical cases, plays
an important role in the treatment decision process. Simultaneously the surgeon has to keep track of a large
amount of clinical data, emerging from a number of heterogeneous systems during all phases of surgical treatment.
This is complemented with the constantly growing knowledge derived from clinical studies and literature. To
recall this vast amount of information at the right moment poses a growing challenge that should be supported
by adequate technology.
While many tools and projects aim at sharing or integrating data from various sources or even provide knowledge-based
decision support - to our knowledge - no concept has been proposed that addresses the entire surgical
pathway by accessing the entire information in order to provide context-aware cognitive assistance. Therefore a
semantic representation and central storage of data and knowledge is a fundamental requirement.
We present a semantic data infrastructure for integrating heterogeneous surgical data sources based on a common
knowledge representation. A combination of the Extensible Neuroimaging Archive Toolkit (XNAT) with semantic
web technologies, standardized interfaces and a common application platform enables applications to access and
semantically annotate data, perform semantic reasoning and eventually create individual context-aware surgical
The infrastructure meets the requirements of a cognitive surgical assistant system and has been successfully
applied in various use cases. The system is based completely on free technologies and is available to the community
as an open-source package.
Proc. SPIE. 9786, Medical Imaging 2016: Image-Guided Procedures, Robotic Interventions, and Modeling
KEYWORDS: Data modeling, Surgery, Image processing, Numerical simulations, Computer simulations, Medical imaging, Data processing, Cognition, Intelligence systems, Computer architecture, Data integration, Information science
For cardiac surgeons, mitral valve reconstruction (MVR) surgery is a highly demanding procedure, where an artificial annuloplasty ring is implanted onto the mitral valve annulus to re-enable the valve's proper closing functionality. For a successful operation the surgeon has to keep track of a variety of relevant impact factors, such as patient-individual medical history records, valve geometries, or tissue properties of the surgical target, and thereon-based deduce type and size of the best-suitable ring prosthesis according to practical surgery experience. With this work, we aim at supporting the surgeon in selecting this ring prosthesis by means of a comprehensive information processing pipeline. It gathers all available patient-individual information, and mines this data according to 'surgical rules', that represent published MVR expert knowledge and recommended best practices, in order to suggest a set of potentially suitable annuloplasty rings. Subsequently, these rings are employed in biomechanical MVR simulation scenarios, which simulate the behavior of the patient-specific mitral valve subjected to the respective virtual ring implantation. We present the implementation of our deductive system for MVR ring selection and how it is integrated into a cognitive data processing pipeline architecture, which is built under consideration of Linked Data principles in order to facilitate holistic information processing of heterogeneous medical data. By the example of MVR surgery, we demonstrate the ease of use and the applicability of our development. We expect to essentially support patient-specific decision making in MVR surgery by means of this holistic information processing approach.
A mitral valve reconstruction (MVR) is a complex operation in which the functionality of incompetent mitral valves is re-established by applying surgical techniques. This work deals with predictive biomechanical simulations of operation scenarios for an MVR, and the simulation's integration into a knowledge-based surgery assistance system. We present a framework for the definition of the corresponding surgical workflow, which combines semantically enriched surgical expert knowledge with a biomechanical simulation. Using an ontology, 'surgical rules' which describe decision and assessment criteria for surgical decision-making are represented in a knowledge base. Through reasoning these 'rules' can then be applied on patient-specific data in order to be converted into boundary conditions for the biomechanical soft tissue simulation, which is based on the Finite Elements Method (FEM). The simulation, which is implemented in the open-source C++ FEM software HiFlow<sup>3</sup>, is controlled via the Medical Simulation Markup Language (MSML), and makes use of High Performance Computing (HPC) methods to cope with real-time requirements in surgery. The simulation results are presented to surgeons to assess the quality of the virtual reconstruction and the consequential remedial effects on the mitral valve and its functionality. The whole setup has the potential to support the intraoperative decision-making process during MVR where the surgeon usually has to make fundamental decision under time pressure.
To date, cardiovascular surgery enables the treatment of a wide range of aortic pathologies. One of the current challenges in this field is given by the detection of high-risk patients for adverse aortic events, who should be treated electively. Reliable diagnostic parameters, which indicate the urge of treatment, have to be determined. Functional imaging by means of 4D phase contrast-magnetic resonance imaging (PC-MRI) enables the time-resolved measurement of blood flow velocity in 3D. Applied to aortic phantoms, three dimensional blood flow properties and their relation to adverse dynamics can be investigated in vitro. Emerging ”in silico” methods of numerical simulation can supplement these measurements in computing additional information on crucial parameters. We propose a framework that complements 4D PC-MRI imaging by means of numerical simulation based on the Finite Element Method (FEM). The framework is developed on the basis of a prototypic aortic phantom and validated by 4D PC-MRI measurements of the phantom. Based on physical principles of biomechanics, the derived simulation depicts aortic blood flow properties and characteristics. The framework might help identifying factors that induce aortic pathologies such as aortic dilatation or aortic dissection. Alarming thresholds of parameters such as wall shear stress distribution can be evaluated. The combined techniques of 4D PC-MRI and numerical simulation can be used as complementary tools for risk-stratification of aortic pathology.