Enhanced 3D-Visualization of Intracranial Aneurysms Involving the Skull Base

Direct volume visualization has recently gained importance as a tool for the analysis of intracranial aneurysms focused on therapy planning. CT-angiography (CTA) intensities are mapped to color and opacity values by so called one-dimensional transfer functions. In this work, we introduce 3D-visualization of intracranial aneurysms making use of transfer functions based on measured values and gradient magnitudes extracted from the CTA data. Furthermore, we present a tool for the creation of 2D transfer functions in the clinical environment. The visualization application runs on standard PCs equipped with modern 3D graphics cards. Evaluations were carried out on 17 clinical cases from our archive. Clear improvements with respect to standard volume visualization were observed especially in the area of the skull base, where the arteries are difficult to separate from the bone. Effective separation of skull and arteries was achieved even for cases where the critical vascular structures were embedded in osseous tissue.