title: Reduction of dental metallic artefacts in CT: value of a newly developed algorithm for metal artefact reduction (O-MAR).
abstract: OBJECTIVE
  To evaluate the image quality of O-MAR (Metal Artifact Reduction for Orthopedic Implants) for dental metal artefact reduction.
  
  
  METHODS
  This prospective study received institutional review board approval and written informed consent was obtained. Thirty patients who had dental implants or dental fillings were included in this study. Computed tomography (CT) images were obtained through the oral cavity and neck during the portal venous phase. The system reconstructed the O-MAR-processed images in addition to the uncorrected images. CT attenuation and image noise of the soft tissue of the oral cavity were compared between the O-MAR and the uncorrected images. Qualitative analysis was undertaken between the two image groups.
  
  
  RESULTS
  The image noise of the O-MAR images was significantly lower than that of the uncorrected images (p < 0.01). O-MAR offered plausible attenuations of soft tissue compared with non-O-MAR. Better qualitative scores were obtained in the streaking artefacts and the degree of depiction of the oral cavity with O-MAR compared with non-O-MAR.
  
  
  CONCLUSIONS
  O-MAR enables the depiction of structures in areas in which this was not previously possible due to dental metallic artefacts in qualitative image analysis. O-MAR images may have a supplementary role in addition to uncorrected images in oral diagnosis.
authors.affiliation: Diagnostic Radiology, Amakusa Medical Center, Amakusa, Kumamoto, Japan; Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, Honjo, Kumamoto, Japan. Electronic address: masafkidoh@yahoo.co.jp.
authors.forename: M
authors.initials: M
authors.lastname: Kidoh
authors.affiliation: Diagnostic Radiology, Amakusa Medical Center, Amakusa, Kumamoto, Japan; Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, Honjo, Kumamoto, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakaura
authors.affiliation: Diagnostic Radiology, Amakusa Medical Center, Amakusa, Kumamoto, Japan; Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, Honjo, Kumamoto, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: Philips Electronics, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tokuyasu
authors.affiliation: Philips Electronics, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Osakabe
authors.affiliation: Department of Surgery, Amakusa Medical Center, Amakusa, Kumamoto, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Harada
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, Honjo, Kumamoto, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D016477:Artifacts; D003287:Contrast Media; D015921:Dental Implants; D003793:Dental Restoration, Permanent; D005260:Female; D006801:Humans; D008297:Male; D008670:Metals; D008875:Middle Aged; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D015921:Dental Implants; D008670:Metals