title: Generating a normalized geometric liver model using warping.
abstract: OBJECTIVE
  Automated liver surface determination in abdominal computed tomography scans, currently difficult to achieve, is of interest to determine liver location and size for various medical applications, including radiation therapy treatment planning, surgical planning, and oncologic monitoring. The authors propose to facilitate automation by the addition of a priori shape information in the form of a liver model.
  
  
  METHODS
  The normalized geometric liver model is generated by averaging outlines from a set of normal liver studies previously registered using thin-plate spline warping. The model consists of an averaged liver surface, a set of anatomic landmarks, and a deformation function.
  
  
  RESULTS
  A liver model is presented and its ability to represent normal liver shapes is demonstrated.
  
  
  CONCLUSIONS
  Liver surface warping provides a means of data normalization for model construction and a means of model deformation for representation of liver organ shapes.
authors.affiliation: Department of Radiology, University of Michigan, Ann Arbor.
authors.forename: J L
authors.initials: JL
authors.lastname: Boes
authors.forename: P H
authors.initials: PH
authors.lastname: Bland
authors.forename: T E
authors.initials: TE
authors.lastname: Weymouth
authors.forename: L E
authors.initials: LE
authors.lastname: Quint
authors.forename: F L
authors.initials: FL
authors.lastname: Bookstein
authors.forename: C R
authors.initials: CR
authors.lastname: Meyer
mesh_terms: D003198:Computer Simulation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008099:Liver / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed