Traditional volume visualization techniques may provide incomplete clinical information needed for many applications in medical visualization. Especially in the area of vascular visualization important features such as the patent lumen of a diseased vessel segment may not be visible. Curved Planar Reformation (CPR) has proven to be an acceptable practical solution. Existing CPR techniques, however, still have diagnostically relevant limitations. In this paper we introduce two advanced methods for efficient vessel visualization, based on the concept of CPR. Both methods benefit from relaxation of spatial coherence in favor of improved feature perception. We present a new technique to visualize the interior of a vessel in a single image. A vessel is re-sampled along a spiral around the vessel central axis. The helical spiral depicts the vessel volume. Furthermore, a method to display an entire vascular tree without mutually occluding vessels is presented. Minimal rotations around the br...