title: An in vitro comparison of the accuracy of measurements obtained from high- and low-resolution cone-beam computed tomography scans.
abstract: BACKGROUND
  This study aimed to investigate in an ex vivo model the reduction in patient radiation dose while maintaining accurate linear measurements by comparing cone-beam computed tomography (CBCT) scans taken at 360° versus 180° rotation, with porcine jaw specimens as a reference standard.
  
  
  METHODS
  CBCT scans of 12 sectioned porcine hemimandibles at 360° and 180° rotations were taken with standardized clinical exposure parameters. To assess interobserver variability, 6 assessors who were blinded to the degree of rotation took linear measurements of anatomic structures on each scan. The measurements were repeated after 2 weeks to assess intraobserver variability. Accuracy of measurement was judged against the corresponding measurements taken from the porcine jaw specimens.
  
  
  RESULTS
  Intraclass correlations signaled good-to-excellent intraobserver and interobserver agreement (0.65-0.98 and 0.79-0.98), respectively. Mixed regression analysis found no significant difference between the measurements from 180° or 360° rotations and no difference between the 2 rotations and porcine jaw specimens.
  
  
  CONCLUSIONS
  A CBCT image sufficient to make accurate clinical measurements with a reduced radiation exposure may be obtained by using 180° rotation of the CBCT tube head.
authors: Unit of Conservative Dentistry, King's College London, Dental Institute at Guy's Hospital, King's Health Partners, London, United Kingdom. danya.hashem@kcl.ac.uk
authors: Danya
authors: D
authors: Hashem
authors: Jackie E
authors: JE
authors: Brown
authors: Shanon
authors: S
authors: Patel
authors: Francesco
authors: F
authors: Mannocci
authors: Ana Nora
authors: AN
authors: Donaldson
authors: Timothy F
authors: TF
authors: Watson
authors: Avijit
authors: A
authors: Banerjee
mesh_terms: D000818:Animals; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D061827:Dimensional Measurement Accuracy; D008334:Mandible / Q000000981:diagnostic imaging*; D015588:Observer Variation; D011829:Radiation Dosage; D012391:Root Resorption / Q000000981:diagnostic imaging*; D013552:Swine