title: Accuracy and precision of spiral CT in the assessment of neoplastic lesions associated with the mandible.
abstract: OBJECTIVE
  The purpose of this study was to determine the accuracy (validity) and precision (reliability) of spiral computed tomographic (CT) images by using film- and computer graphics-based measurements of simulated neoplastic lesions associated with the mandible.
  
  
  METHODS
  Four cadaver heads, each with two simulated tumors containing contrast medium positioned medial to the mandibles, were examined by using a subsecond spiral CT scanner. Data were transferred to film and to a computer workstation. With computer graphics, data were analyzed by using multiplanar reconstructed images. Linear measurements of the length, width, and depth of simulated tumors were made by two observers, twice each, on the film scans by using manual calipers and on the multiplanar reconstructed images by using computerized measurements. The soft tissues were then removed from the cadavers and the same measurements made by using the same calipers.
  
  
  RESULTS
  No statistically significant differences between computer graphics- or film-based measurements and physical measurements (P > .05) or between inter- and intraobserver measurements (P > .05) were found.
  
  
  CONCLUSIONS
  The authors found high reproducibility of measurements for all dimensions. Spiral CT allows accurate computer graphics- and film-based measurements of neoplastic lesions associated with the mandible.
authors.affiliation: Department of Radiology, Faculty of Odontology, University of São Paulo, Brazil.
authors.forename: M G
authors.initials: MG
authors.lastname: Cavalcanti
authors.forename: A
authors.initials: A
authors.lastname: Ruprecht
authors.forename: J M
authors.initials: JM
authors.lastname: Bonomie
authors.forename: M W
authors.initials: MW
authors.lastname: Vannier
mesh_terms: D000368:Aged; D003196:Computer Graphics; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008334:Mandible; D008339:Mandibular Neoplasms / Q000000981:diagnostic imaging*; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed