Vessel extraction in medical images by 3D wave propagation and traceback

This paper presents an approach for the extraction of vasculature from a volume of Magnetic Resonance Angiography (MRA) images by using a 3D wave propagation and traceback mechanism. We discuss both the theory and the implementation of the approach. Using a dual-sigmoidal filter, we label each voxel in the MRA volume with the likelihood that it is within a vessel. Representing the reciprocal of this likelihood image as an array of refractive indices, we propagate a digital wave through the volume from the base of the vascular tree. This wave ´washes´ over the vasculature and extracts the vascular tree, ignoring local noise perturbations. While the approach is inherently SIMD we present an efficient sequential algorithm for the wave propagation, and discuss the traceback algorithm. We demonstrate the effectiveness of our integer image neighborhood-based algorithm and its robustness to image noise.