title: Effect of voxel size on the accuracy of 3D reconstructions with cone beam CT.
abstract: OBJECTIVE
  The various types of cone beam CT (CBCT) differ in several technical characteristics, notably their spatial resolution, which is defined by the acquisition voxel size. However, data are still lacking on the effects of voxel size on the metric accuracy of three-dimensional (3D) reconstructions. This study was designed to assess the effect of isotropic voxel size on the 3D reconstruction accuracy and reproducibility of CBCT data.
  
  
  METHODS
  The study sample comprised 70 teeth (from the Institut d'Anatomie Normale, Strasbourg, France). The teeth were scanned with a KODAK 9500 3D® CBCT (Carestream Health, Inc., Marne-la-Vallée, France), which has two voxel sizes: 200 µm (CBCT 200 µm group) and 300 µm (CBCT 300 µm group). These teeth had also been scanned with the KODAK 9000 3D® CBCT (Carestream Health, Inc.) (CBCT 76 µm group) and the SCANCO Medical micro-CT XtremeCT (SCANCO Medical, Brüttisellen, Switzerland) (micro-CT 41 µm group) considered as references. After semi-automatic segmentation with AMIRA® software (Visualization Sciences Group, Burlington, MA), tooth volumetric measurements were obtained.
  
  
  RESULTS
  The Bland-Altman method showed no difference in tooth volumes despite a slight underestimation for the CBCT 200 µm and 300 µm groups compared with the two reference groups. The underestimation was statistically significant for the volumetric measurements of the CBCT 300 µm group relative to the two reference groups (Passing-Bablok method).
  
  
  CONCLUSIONS
  CBCT is not only a tool that helps in diagnosis and detection but it has the complementary advantage of being a measuring instrument, the accuracy of which appears connected to the size of the voxels. Future applications of such measurements with CBCT are discussed.
authors.affiliation: Laboratoire Anthropologie Moléculaire et Imagerie de Synthèse, Faculté de Chirurgie Dentaire, Université Paul Sabatier, Centre Hospitalier Universitaire, Service de Médecine Légale, Hôpital de Rangueil, 37 allées J Guesde, 31000 Toulouse, France. delphine_maret@yahoo.fr
authors.forename: D
authors.initials: D
authors.lastname: Maret
authors.forename: N
authors.initials: N
authors.lastname: Telmon
authors.forename: O A
authors.initials: OA
authors.lastname: Peters
authors.forename: B
authors.initials: B
authors.lastname: Lepage
authors.forename: J
authors.initials: J
authors.lastname: Treil
authors.forename: J M
authors.initials: JM
authors.lastname: Inglèse
authors.forename: A
authors.initials: A
authors.lastname: Peyre
authors.forename: J L
authors.initials: JL
authors.lastname: Kahn
authors.forename: M
authors.initials: M
authors.lastname: Sixou
mesh_terms: D002675:Child, Preschool; D054893:Cone-Beam Computed Tomography / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods* / Q000706:statistics & numerical data; D021621:Imaging, Three-Dimensional / Q000379:methods* / Q000706:statistics & numerical data; D007223:Infant; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging; D009811:Odontometry / Q000706:statistics & numerical data; D011856:Radiographic Image Enhancement / Q000379:methods; D015203:Reproducibility of Results; D012984:Software; D014083:Tooth Germ / Q000000981:diagnostic imaging*; D055114:X-Ray Microtomography / Q000295:instrumentation / Q000379:methods