title: Automated centerline for computed tomography colonography.
abstract: OBJECTIVE
  A novel method to compute the centerline of the human colon obtained from computed tomography colonography is proposed. Two applications of this method are demonstrated: to compute local colonic distension (caliber), and to match polyps on supine and prone images.
  
  
  METHODS
  The centerline algorithm involves multiple steps including simplification of the colonic surface by decimation; thinning of the decimated colon to create a preliminary centerline; selection of equally spaced points on the preliminary centerline; grouping neighboring points; and mapping them back to rings in the original colon. This method was tested on 20 human computed tomography colonography datasets (supine and prone examinations of 10 patients) and on a computer-generated colon phantom.
  
  
  RESULTS
  Visual inspection of the colons and their centerlines showed the centerline to be accurate. For the colon phantom, the average error was only 1 mm. For 11 polyps visualized in both the supine and prone positions and found by computer-aided detection, the normalized distance along the centerline to each polyp was not significantly different on the supine and prone views (r = 0.999; P < .001).
  
  
  CONCLUSIONS
  This method produces an accurate colon centerline that may be useful for flight path planning, matching detections on the supine and prone views, and computing local colonic distension.
authors: Department of Radiology, National Institutes of Health, Building 10, Room 1C660, 10 Center Dr, MSC 1182, Bethesda, MD 20892-1182, USA.
authors: Gheorghe
authors: G
authors: Iordanescu
authors: Ronald M
authors: RM
authors: Summers
mesh_terms: D000465:Algorithms; D003106:Colon / Q000000981:diagnostic imaging; D003111:Colonic Polyps / Q000000981:diagnostic imaging; D023881:Colonography, Computed Tomographic / Q000379:methods*; D006801:Humans; D019047:Phantoms, Imaging; D016684:Prone Position; D016683:Supine Position