title: Abdominal image segmentation using three-dimensional deformable models.
abstract: OBJECTIVE
  The authors develop a three-dimensional (3-D) deformable surface model-based segmentation scheme for abdominal computed tomography (CT) image segmentation.
  
  
  METHODS
  A parameterized 3-D surface model was developed to represent the human abdominal organs. An energy function defined on the direction of the image gradient and the surface normal of the deformable model was introduced to measure the match between the model and image data. A conjugate gradient algorithm was adapted to the minimization of the energy function.
  
  
  RESULTS
  Test results for synthetic images showed that the incorporation of surface directional information improved the results over those using only the magnitude of the image gradient. The algorithm was tested on 21 CT datasets. Of the 21 cases tested, 11 were evaluated visually by a radiologist and the results were judged to be without noticeable error. The other 10 were evaluated over a distance function. The average distance was less than 1 voxel.
  
  
  CONCLUSIONS
  The deformable model-based segmentation scheme produces robust and acceptable outputs on abdominal CT images.
authors.affiliation: The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA.
authors.forename: L
authors.initials: L
authors.lastname: Gao
authors.forename: D G
authors.initials: DG
authors.lastname: Heath
authors.forename: E K
authors.initials: EK
authors.lastname: Fishman
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007668:Kidney / Q000033:anatomy & histology*; D008953:Models, Anatomic; D014057:Tomography, X-Ray Computed / Q000379:methods