author = "Osorio, Am{\'{\i}}lcar Remigio and Isoardi, Roberto Andr{\'e}s 
                         and Mato, Germ{\'a}n",
          affiliation = "Fundaci{\'o}n Centro Diagn{\'o}stico Nuclear, Buenos Aires, 
                         Argentina and Fundaci{\'o}n Escuela de Medicina Nuclear, Mendoza, 
                         Argentina and Grupo F{\'{\i}}sica Estad{\'{\i}}stica, Centro 
                         At{\'o}mico Bariloche, Bariloche, Argentina",
                title = "Deformable CT registration using Fourier basis functions in 3D",
            booktitle = "Proceedings...",
                 year = "2010",
               editor = "Bellon, Olga and Esperan{\c{c}}a, Claudio",
         organization = "Conference on Graphics, Patterns and Images, 23. (SIBGRAPI)",
            publisher = "IEEE Computer Society",
              address = "Los Alamitos",
             keywords = "Image segmentation, Bayesian analysis, MRI.",
             abstract = "Non-rigid medical image registration is an essential tool when 
                         studying deformable regions such as thorax and abdomen. In this 
                         paper we propose an algorithm based on Fourier transformations 
                         with trigonometric Fourier basis functions at different orders 
                         combined with a subdivision scheme in order to attain spatial 
                         alignment of two corresponding Computed Tomography (CT) volumes, 
                         with small to moderate deformations. The performance of the 
                         algorithm was analyzed as a function of the transformation order 
                         (n) and the number of volume subdivisions along each axis (s). The 
                         results show that a suitable parameter choice is n=2, s=3-4. The 
                         algorithm was validated by correcting clinical images previously 
                         deformed with Thin-Plate Splines (TPS), and also applied to 
                         coregister different scans of a given subject after repositioning 
                         on the scanner bed. This method is automatic and does not require 
                         previous segmentation or landmark selection. Average registration 
                         errors with the optimal parameters were estimated in approximately 
                         3 mm, and typical computing time is of the order of a few minutes 
                         in a standard personal computer. We have found that Fourier basis 
                         functions provide an efficient way to implement non-rigid 
  conference-location = "Gramado",
      conference-year = "Aug. 30 - Sep. 3, 2010",
             language = "en",
           targetfile = "70636-jul05.pdf",
        urlaccessdate = "2020, Nov. 26"