Reconstruction of 3-D geometry using 2-D profiles and a geometric prior model

A method has been developed to reconstruct three-dimensional (3-D) surfaces from two-dimensional (2-D) projection data. It is used to produce individu alized boundary element models, consisting of thorax and lung surfaces, for electro- and magnetocardiographic inverse problems. Two orthogonal project ions are utilized, A geometrical prior model, built: using segmented magnet ic resonance images, is deformed according to profiles segmented from proje ction images. In our method, virtual X-ray images of the prior model are fi rst constructed by simulating real X-ray imaging, The 2-D profiles of the m odel are segmented from the projections and elastically matched with the pr ofiles segmented from patient data. The displacement vectors produced by th e elastic 2-D matching are back projected onto the 3-D surface of the prior model. Finally, the model is deformed, using the back-projected vectors. T wo different deformation methods are proposed, The accuracy of the method i s validated by a simulation, The average reconstruction error of a thorax a nd lungs was 1.22 voxels, corresponding to about 5 mm.