ESTIMATION OF 3-D SHAPE OF BLOOD VESSELS FROM X-RAY IMAGES.

A new approach to blood vessel boundary estimation from a few whole volume projection images addressing the problems of low S/N ratio, low sampling rate, optimum data utilization, and the clinical need for three-dimensional information about the vessel is presented. It is based on a recently developed estimation approach and algorithm for 3-D reconstruction from projections with incomplete and very noisy data. Using a stochastic dynamic model for the vessel, the imaging problem is reformulated as a nonlinear state estimation problem of small dimensionality, and an approximate recursive MMSE smoothing algorithm for its solution is presented. Computationally, the algorithm outperforms by orders of magnitude a previously suggested estimation method for blood vessel imaging that was infeasible for the 3-D problem.