title: Evaluation of a cone beam CT artefact reduction algorithm.
abstract: OBJECTIVE
  An algorithm and software to reduce metal artefact has been developed recently and is available in the Picasso Master 3D® (VATECH, Hwaseong, Republic of Korea), which under visual assessment produces better quality images than were obtainable previously. The objective of this in vitro study was to investigate whether the metal artefact reduction (MAR) algorithm of the Picasso Master 3D machine reduced the incidence of metal artefacts and increased the contrast-to-noise ratio (CNR) while maintaining the same gray value when there was no metallic body present within the scanned volume.
  
  
  METHODS
  20 scans with a range of 50-90 kVp were acquired, of which 10 had a metallic bead inserted within a phantom. The images obtained were analysed using public domain software (ImageJ; NIH Image, Bethesda, MD). Area histograms were used to evaluate the mean gray level variation of the epoxy resin-based substitute (ERBS) block and a control area. The CNR was calculated.
  
  
  RESULTS
  The MAR algorithm increased the CNR when the metallic bead was present; it enhanced the ERBS gray level independently of the presence of the metallic bead. The image quality also improved as peak tube potential was increased.
  
  
  CONCLUSIONS
  Improved quality of images and regaining of the control gray values of a phantom were achieved when the MAR algorithm was used in the presence of a metallic bead.
authors.affiliation: Department of Comprehensive Dentistry, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA. boulosbchara@hotmail.com
authors.forename: B
authors.initials: B
authors.lastname: Bechara
authors.forename: C A
authors.initials: CA
authors.lastname: McMahan
authors.forename: H
authors.initials: H
authors.lastname: Geha
authors.forename: M
authors.initials: M
authors.lastname: Noujeim
mesh_terms: D000465:Algorithms; D016477:Artifacts; D054893:Cone-Beam Computed Tomography; D006801:Humans; D016014:Linear Models; D008670:Metals; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement; D011857:Radiographic Image Interpretation, Computer-Assisted; D012984:Software
chemical_list: D008670:Metals