title: Effects of orthodontic appliances on the diagnostic quality of magnetic resonance images of the head.
abstract: BACKGROUND
  The influence of 4 commonly used fixed orthodontic appliances on artifact formation and diagnostic quality of magnetic resonance (MR) images of the head produced by a 3-T MR scanner was studied.
  
  
  METHODS
  Stainless steel brackets, ceramic brackets, combination of ceramic brackets and steel molar tubes, and multistranded steel mandibular lingual retainers were embedded into custom-made trays for each of 10 adult subjects. Head MR scans of 9 regions were acquired for each subject wearing these trays. Sagittal T1-weighted, axial T2-weighted, axial gradient-recalled, axial diffusion-weighted, noncontrast axial MR angiography, and axial fluid-attenuated inversion recovery MR sequences were included. Two neuroradiologists evaluated image distortions and diagnostic qualities of the 1314 acquired images (13860 image slices).
  
  
  RESULTS
  The images were affected by appliance, head region, and MR sequence. Stainless steel brackets and molar tubes affected the images the most, and ceramic brackets caused minimal image distortion.
  
  
  CONCLUSIONS
  Head MR images are differentially affected by orthodontic appliances. The appliance, region imaged, and MR sequence should be considered before imaging patients wearing fixed orthodontic appliances.
authors.affiliation: Private Practice, Ottawa, Ontario, Canada.
authors.forename: Dzmitry
authors.initials: D
authors.lastname: Zhylich
authors.affiliation: Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Pradeep
authors.initials: P
authors.lastname: Krishnan
authors.affiliation: Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Prakash
authors.initials: P
authors.lastname: Muthusami
authors.affiliation: Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Tammy
authors.initials: T
authors.lastname: Rayner
authors.affiliation: Department of Medical Imaging, University of Toronto; Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Manohar
authors.initials: M
authors.lastname: Shroff
authors.affiliation: Department of Medical Imaging, University of Toronto; Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Andrea
authors.initials: A
authors.lastname: Doria
authors.affiliation: Discipline of Orthodontics, Faculty of Dentistry, University of Toronto; Division of Orthodontics, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Bryan
authors.initials: B
authors.lastname: Tompson
authors.affiliation: Division of Biostatistics, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Wendy
authors.initials: W
authors.lastname: Lou
authors.affiliation: Discipline of Orthodontics, Faculty of Dentistry, University of Toronto; Division of Orthodontics, Hospital for Sick Children, Toronto, Ontario, Canada. Electronic address: sunjaysuri@hotmail.com.
authors.forename: Sunjay
authors.initials: S
authors.lastname: Suri
mesh_terms: D000328:Adult; D016477:Artifacts; D002516:Ceramics; D005260:Female; D006257:Head / Q000033:anatomy & histology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009967:Orthodontic Appliances; D013193:Stainless Steel
chemical_list: D013193:Stainless Steel