Focus and context for volume visualization

Abstract

Scientific investigation and simulation have been producing increasingly large datasets. Usually that kind of data is visualized employing some scientific visualization technique. Another related field, information visualization, deals with non-scientific large scale data, using different approaches to achieve an effective understanding. In this thesis, we aim to apply information visualization concepts to a scientific visualization approach: volume rendering. We demonstrate this idea through a practical application: the effective visualization of cerebral aneurysms. This is a very important issue in the field of neurosurgery, usually carried out through the visualization systems offered by the imaging equipment being used. However, the use of those systems in the operating theatre is not commonly possible, as the system requires the equipment to be present and the user interface is frequently too complex. In addition to that, usually it is difficult to display both the aneurysm with sufficient detail, and the vessel network of the brain at the same time. Hence in this thesis we introduce a framework for volume visualization, where the idea of spatial distortion is combined with other novel effects to achieve an effective visual result - this builds on the information visualization concept of focus and context. The framework was implemented through direct programming of the graphics processor and integrated into a volume rendering system. The application was evaluated by a number of medical professionals related to the field of neurosurgery, and we present an analysis of the results