Burkhard Wünsche - Visualization of Diffusion Tensor Imaging Data
Diffusion tensor imaging (DTI) is used to measure the intrinsic properties of water diffusion in the brain by an orientation invariant quantity, the diffusion tensor D. By anaysing the diffusion tensor field it is possible to reconstruct and visualize various anatomical structures of the brain as shown in the images below.
Burkhard Wünsche - The Visualization and Measurement of Left Ventricular Deformation
While medical progress has been made in the diagnosis and treatment of heart diseases it remains the biggest killer in the western world. Cardiovascular diseases cause considerable morbidity and the prognosis after heart failure is poor. An improved understanding of cardiac mechanics might advance the diagnosis and treatment of heart diseases.
We have developed techniques for visualizing and evaluating biomedical finite element models and we have demonstrated their application to biomedical data sets by using as an example two models of a healthy and a diseased human left ventricle.
Burkhard Wünsche - A Toolkit for Visualizing Biomedical Data Sets
Medical data sets now comprise a diverse range of measurements such as tissue densities, sensitivity to magnetization, blood flow velocity, and material strain. The size and complexity of medical data sets makes it increasingly difficult to understand, compare, analyze and communicate the data. Visualization is an attempt to simplify these tasks according to the motto "An image says more than a thousand words". Representing complex material properties, such as strain, as a single image improves the perception of features and pattern in the data, enables the recognition of relationship between different measures and facilitates the navigation through and interaction with complex and disparate sets of data.
We have developed a visualization toolkit for exploring complex biomedical data sets. The tool has a modular design which facilitates the comparison and exploration of multiple data sets and visualizations. The tool accepts as input a wide variety of data sets including finite element models for which fields can be represented both in material and world coordinates. A novel field data structure allows interactive creation of new fields and boolean filters function as a universal visualization tool. A wide variety of visualization techniques are implemented and several improvements and new techniques have been developed.
Jing Li - Experiences with and Assessment of VTK for Teaching and Practicing Biomedical Visualization
VTK is a popular freely available object-oriented visualization toolkit. In this project we asssess the suitability of VTK for visualizing biomedical data sets and its suitability as a teaching tool in a visualization course. We are also exploring ways to extend the capabilities of the toolkit.
Zheng (Jenny) Lin - A Fast Ambiguity-Free Polygonization Method for Biomedical Imaging Data Sets
The marching cube algorithm is an efficient and popular method for constructing isosurfaces from a density field. However, the original Marching cube algorithm suffers from ambiguities, i.e. two neighbouring cubes may connect the intersection points of the isosurface with a shared face differently, which results in a hole in the isosurface. In biomedical imaging such artifacts are not acceptable since they lead to a wrong interpretation of the data set potentially resulting in a wrong diagnosis. In this project we modify the Marching Cubes algorithm so that it uses an extended table for all topological different polygonisations of ambiguous configuration. We have developed a fast method for determining the correct cube topology and obtain the correct cube configuration by indexing this extended table. Using hash tables for computing sample coordinates and mesh vertices and vertex normals further improves the efficiency of this algorithm.