title: Intraobserver and interobserver reproducibility in linear measurements on axial images obtained by cone-beam computed tomography.
abstract: OBJECTIVE
  This study was performed to investigate the intra- and inter-observer variability in linear measurements with axial images obtained by PreXion (PreXion Inc., San Mateo, USA) and i-CAT (Imaging Sciences International, Xoran Technologies Inc., Hatfield, USA) CBCT scanners, with different voxel sizes.
  
  
  METHODS
  A cylindrical object made from nylon with radiopaque markers (phantom) was scanned by i-CAT and PreXion 3D devices. For each axial image, measurements were taken twice in the horizontal (distance A-B) and vertical (distance C-D) directions, randomly, with a one-week interval between measurements, by four oral radiologists with five years or more experience in the use of these measuring tools.
  
  
  RESULTS
  All of the obtained linear measurements had lower values than those of the phantom. The statistical analysis showed high intra- and inter-observer reliability (p=0.297). Compared to the real measurements, the measurements obtained using the i-CAT device and PreXion tomography, on average, revealed absolute errors ranging from 0.22 to 0.59 mm and from 0.23 to 0.63 mm, respectively.
  
  
  CONCLUSIONS
  It can be concluded that both scanners are accurate, although the linear measurements are underestimations, with no significant differences between the evaluators.
authors.affiliation: São Leopoldo Mandic Research Center, Department of Oral Radiology, College of Dentistry, São Paulo, SP, Brazil.
authors.forename: Nathália Cristine
authors.initials: NC
authors.lastname: da Silva
authors.affiliation: Department of Oral Radiology, College of Dentistry, Catholic University of Brasilia, São Paulo, SP, Brazil.
authors.forename: Maurício
authors.initials: M
authors.lastname: Barriviera
authors.affiliation: São Leopoldo Mandic Research Center, Department of Oral Radiology, College of Dentistry, São Paulo, SP, Brazil.
authors.forename: José Luiz Cintra
authors.initials: JL
authors.lastname: Junqueira
authors.affiliation: São Leopoldo Mandic Research Center, Department of Oral Radiology, College of Dentistry, São Paulo, SP, Brazil.
authors.forename: Francine Kühl
authors.initials: FK
authors.lastname: Panzarella
authors.affiliation: São Leopoldo Mandic Research Center, Department of Oral Radiology, College of Dentistry, São Paulo, SP, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Raitz
keywords: Cone-Beam Computed Tomography; Dimensional Measurement Accuracy; Reproducibility of Results