Interactive and intuitive visualization of small and complex vascular structures in MR and CT

The spatial understanding of vascular information obtained with CT and MR is tremendously assisted by direct volume rendering since-it provides semi-transparent views of the entire data giving insight to hidden structures. Ensuring a convenient diagnosis of complex vessel topology, the authors propose an approach based on 3D texture mapping which ensures interactive frame rates. The method proved to be very suitable for the visualization of intracranial aneurysms within CTA and MRA. Its full value is demonstrated by meaningful representations of the inner ear and of tiny vessels in the spinal channel obtained with a MR 3D-CISS sequence. Since a small portion of the whole data is often sufficient for a more detailed investigation, a new technique using interactive clipping of arbitrary geometry, as presented in (R. Westermann and T. Ertl, “Efficiently using graphics hardware in volume rendering applications.” In SIGGRAPH 98, Conf. Proc., 1998), was evaluated. The integration into OpenInventor ensures intuitive manipulation of the volume and the clipping geometries. For further anatomical orientation and the comparison to DSA different registration procedures are applied