title: Mucosal detail at CT virtual reality: surface versus volume rendering.
abstract: OBJECTIVE
  To evaluate computed tomographic virtual reality with volumetric versus surface rendering.
  
  
  METHODS
  Virtual reality images were reconstructed for 27 normal or pathologic colonic, gastric, or bronchial structures in four ways: the transition zone (a) reconstructed separately from the wall by using volume rendering; (b) with attenuation equal to air; (c) with attenuation equal to wall (soft tissue); (d) with attenuation halfway between air and wall. The four reconstructed images were randomized. Four experienced imagers blinded to the reconstruction graded them from best to worst with predetermined criteria.
  
  
  RESULTS
  All readers rated images with the transition zone as a separate structure as overwhelmingly superior (P <.001): Nineteen cases had complete concurrence among all readers. The best of the surface-rendering reconstructions had the transition zone attenuation equal to the wall attenuation (P <.001). The third best reconstruction had the transition zone attenuation equal to the air attenuation, and the worst had the transition zone attenuation halfway between the air and wall attenuation.
  
  
  CONCLUSIONS
  Virtual reality is best with volume rendering, with the transition zone (mucosa) between the wall and air reconstructed as a separate structure.
authors.affiliation: Department of Radiology, Milton S. Hershey Medical Center, Pennsylvania State University, 500 University Dr, Hershey, PA 17033, USA. khopper@psu.edu
authors.forename: K D
authors.initials: KD
authors.lastname: Hopper
authors.forename: A T
authors.initials: AT
authors.lastname: Iyriboz
authors.forename: S W
authors.initials: SW
authors.lastname: Wise
authors.forename: J D
authors.initials: JD
authors.lastname: Neuman
authors.forename: D T
authors.initials: DT
authors.lastname: Mauger
authors.forename: C J
authors.initials: CJ
authors.lastname: Kasales
mesh_terms: D000818:Animals; D001995:Bronchography; D003106:Colon / Q000000981:diagnostic imaging; D003111:Colonic Polyps / Q000000981:diagnostic imaging; D005243:Feces; D005753:Gastric Mucosa / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007413:Intestinal Mucosa / Q000000981:diagnostic imaging; D015588:Observer Variation; D011856:Radiographic Image Enhancement; D020545:Respiratory Mucosa / Q000000981:diagnostic imaging; D012756:Sheep; D016037:Single-Blind Method; D013552:Swine; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014132:Trachea / Q000000981:diagnostic imaging; D014584:User-Computer Interface