title: Computed tomographic colonography: comparison of two workstations.
abstract: OBJECTIVE
  To compare two commercially available computed tomography (CT) colonography systems with respect to interobserver variability, the influence of level of expertise, and the gradual reduction of reviewing time for each system.
  
  
  METHODS
  Two residents and two radiologists using Siemens CTAPP Colography software and Viatronix V3D-Colon software reviewed supine and prone CT acquisitions from 24 patients in a primary 3D endoluminal view. The observers graded each case with respect to technical quality and diagnostic value, assessed the presence of pathology, and indicated the time spent on the viewing.
  
  
  RESULTS
  Significant differences were found in technical quality (P < 0.001) and diagnostic value (P<0.001) depending on which system was used, with higher scores for the Viatronix software. The agreement between specialists tended to be higher than that between residents (kappa=0.63 (0.30-0.95) vs. kappa=0.51 (0.21-0.81)), and the residents gave significantly (P < 0.001) higher scores of technical quality. However, the level of expertise had no significant impact on the assessments. We noted extensive variability in pathological lesions found by the different observers. The number of findings did not differ between workstations, but the viewers tended to report larger polyp sizes with the Viatronix software. The time needed for viewing decreased significantly from the first to the last examination viewed by each observer.
  
  
  CONCLUSIONS
  Both the evaluated systems present trustworthy images of the human colon, but in a primary 3D setting the Viatronix software is favored owing to the user-friendly interface, higher experienced technical quality, and better diagnostic value.
authors.affiliation: Center for Medical Image Science and Visualization, Linköping University, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Sörstedt
authors.forename: A
authors.initials: A
authors.lastname: Persson
authors.forename: B
authors.initials: B
authors.lastname: Norén
authors.forename: U
authors.initials: U
authors.lastname: Björnlert
authors.forename: P
authors.initials: P
authors.lastname: Malcherek
authors.forename: M
authors.initials: M
authors.lastname: Axelsson
authors.forename: J
authors.initials: J
authors.lastname: Johansson
authors.forename: O
authors.initials: O
authors.lastname: Smedby
mesh_terms: D000328:Adult; D000368:Aged; D002983:Clinical Competence; D003111:Colonic Polyps / Q000473:pathology; D023881:Colonography, Computed Tomographic / Q000295:instrumentation / Q000592:standards*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D013997:Time Factors