title: Effects of image artifacts on gray-value density in limited-volume cone-beam computerized tomography.
abstract: OBJECTIVE
  An in vitro study was designed to investigate the influence of projection data discontinuity-related artifacts in limited-volume cone-beam computerized tomography (CBCT) imaging of the jaws.
  
  
  METHODS
  Test objects were positioned in 4 patterns in a water-filled phantom as follows: bimandible and vertebrae, bimandible, left mandible and vertebrae, and left mandible. The CT imaging of the left molar region was performed using image intensifier (II)- and flat panel detector (FPD)-based CBCT scanners. The CT value of the mandible and the adjacent soft tissue region were analyzed for density by means of an 8-bit grayscale.
  
  
  RESULTS
  The effects of artifacts were scored as the difference in relative density between the lingual and buccal soft tissue. The intensity of artifacts increased when more objects were presented outside the area being imaged. Fewer artifacts were noted in images produced by the particular FPD CBCT used in this investigation.
  
  
  CONCLUSIONS
  The CBCT system using an FPD resulted in fewer artifacts than the CBCT system using an II in this particular study.
authors: Department of Oral Radiology, Asahi University School of Dentistry, Gifu, Japan. kawamata@dent.asahi-u.ac.jp
authors: Akitoshi
authors: A
authors: Katsumata
authors: Akiko
authors: A
authors: Hirukawa
authors: Shinji
authors: S
authors: Okumura
authors: Munetaka
authors: M
authors: Naitoh
authors: Masami
authors: M
authors: Fujishita
authors: Eiichiro
authors: E
authors: Ariji
authors: Robert P
authors: RP
authors: Langlais
mesh_terms: D016477:Artifacts; D054893:Cone-Beam Computed Tomography; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008334:Mandible / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D013131:Spine / Q000000981:diagnostic imaging