Neugebauer, MathiasJaniga, GaborBeuing, OliverSkalej, MartinPreim, BernhardH. Hauser, H. Pfister, and J. J. van Wijk2014-02-212014-02-2120111467-8659https://doi.org/10.1111/j.1467-8659.2011.01953.xFor cerebral aneurysms, the ostium, the area of inflow, is an important anatomic landmark, since it separates the pathological vessel deformation from the healthy parent vessel. A better understanding of the inflow characteristics, the flow inside the aneurysm and the overall change of pre- and post-aneurysm flow in the parent vessel provide insights for medical research and the development of new risk-reduced treatment options. We present an approach for a qualitative, visual flow exploration that incorporates the ostium and derived anatomical landmarks. It is divided into three scopes: a global scope for exploration of the in- and outflow, an ostium scope that provides characteristics of the flow profile close to the ostium and a local scope for a detailed exploration of the flow in the parent vessel and the aneurysm. The approach was applied to five representative datasets, including measured and simulated blood flow. Informal interviews with two board-certified radiologists confirmed the usefulness of the provided exploration tools and delivered input for the integration of the ostium-based flow analysis into the overall exploration workflow.I.3.6 [Computer Graphics]Methodology and TechniquesInteraction TechniquesI.3.7 [Computer Graphics]Three Dimensional Graphics and RealismColorShadingShadowingTextureI.3.8 [Computer Graphics]Applications