title: Distortion reduction for fast soft straightening of the colon.
abstract: OBJECTIVE
  The purpose of this study was to suppress the geometric distortion associated with soft straightening of the colon by moderately adjusting curved cross sections, which is equivalent to appropriately modifying the underlying electrical field.
  
  
  METHODS
  A computational mechanism to reduce the geometric distortion associated with soft straightening was developed. Because the cause of distortion is uneven sampling of the colon wall with curved cross sections, the curved cross sections formed according to a numerically simulated electrical field were redistributed in the distortion reduction process. This mechanism can be directly incorporated into a previously published fast soft-straightening algorithm. Simulations were performed to evaluate the effectiveness of the mechanism, and a phantom colon with digitally implanted, spherical polyps was straightened and rendered to visually display the efficacy of the mechanism.
  
  
  RESULTS
  The distortion reduction mechanism was advantageous regarding shape preservation of polyps and alleviated distortion substantially. The mechanism occupied only a small portion of the total processing time.
  
  
  CONCLUSIONS
  The distortion reduction mechanism can effectively reduce the geometric distortion associated with soft straightening at little computational cost and has potential for use with computed tomographic colonography.
authors.affiliation: Department of Radiology, University of Iowa Hospitals and Clinics, Iowa City 52242-1077, USA. Zhan-Zhang@ieee.org
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
authors.forename: G
authors.initials: G
authors.lastname: Wang
authors.forename: B P
authors.initials: BP
authors.lastname: Brown
authors.forename: M W
authors.initials: MW
authors.lastname: Vannier
mesh_terms: D000465:Algorithms; D003106:Colon / Q000000981:diagnostic imaging*; D003111:Colonic Polyps / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D019047:Phantoms, Imaging; D014057:Tomography, X-Ray Computed / Q000379:methods*