Reconstruction of asymmetric vessel lumen from two views

We have developed a technique based on epipolar geometry which allows reconstruction of vessel lumina containing asymmetries for arbitrary lumen orientation. Vessel centerlines and the imaging geometry are determined using previously described methods. Epipolar planes are established for pairs of centerline points and intensity profiles are extracted along epipolar lines. Extracted profiles are fitted to projection curves corresponding to elliptical cross-sections. The original vessel intensity profile is subtracted from the best-fit profile yielding the 'plaque' profile. Corresponding best-fit profiles are used to reconstruct elliptical cross sections by backprojecting and identifying ray intersection points which lie within the model cross section. Assuming that the deformation of an otherwise elliptical lumen occurs as a result of plaque growing inward from the periphery, asymmetries are generated by deforming the cross sections to an extent consistent with the plaque profile in both views. The three-dimensional lumen may be obtained by combining individual cross sections in consecutive epipolar planes. The technique was evaluated using noiseless simulated angiograms. Reconstructed asymmetric lumen cross sections were found to be accurate to 95%, where accuracy was determined using area and distance criteria.