title: Visibility of different foreign bodies in the maxillofacial region using plain radiography, CT, MRI and ultrasonography: an in vitro study.
abstract: OBJECTIVE
  To compare the usefulness of four imaging modalities in visualizing various foreign bodies of different sizes.
  
  
  METHODS
  Foreign bodies of four sizes (0.5, 1, 2 and 3 mm) including metal, tooth, wood, plastic, stone, glass and graphite were embedded in six fresh sheep heads on bone surface between the corpus mandible and muscle, and inside the tongue muscle. A human dry skull served as an air-filled space. Plain radiography, CT, MRI and ultrasonography were used, and four skilled radiologists rated the findings individually.
  
  
  RESULTS
  All embedded foreign bodies except wood were best visualized using CT. Wood could only be detected using ultrasonography, and then only when fragments were >0.5 mm in size. Plain radiography and CT were almost equally accurate in visualizing metal and graphite. MRI was the least useful imaging technique.
  
  
  CONCLUSIONS
  In cases with suspected foreign bodies in the maxillofacial region, CT seems to be the optimal initial imaging study. Wood, however, could only be detected using ultrasonography.
authors.affiliation: 1 Department of Radiology, Imam Reza Teaching Center, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran.
authors.forename: R
authors.initials: R
authors.lastname: Javadrashid
authors.forename: D F
authors.initials: DF
authors.lastname: Fouladi
authors.forename: M
authors.initials: M
authors.lastname: Golamian
authors.forename: P
authors.initials: P
authors.lastname: Hajalioghli
authors.forename: M H
authors.initials: MH
authors.lastname: Daghighi
authors.forename: Z
authors.initials: Z
authors.lastname: Shahmorady
authors.forename: M T
authors.initials: MT
authors.lastname: Niknejad
mesh_terms: D000818:Animals; D003952:Diagnostic Imaging / Q000706:statistics & numerical data*; D005547:Foreign Bodies / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005898:Glass; D006108:Graphite; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008334:Mandible / Q000000981:diagnostic imaging / Q000473:pathology*; D008406:Masseter Muscle / Q000000981:diagnostic imaging / Q000473:pathology; D008410:Masticatory Muscles / Q000000981:diagnostic imaging / Q000473:pathology*; D008670:Metals; D010969:Plastics; D011856:Radiographic Image Enhancement / Q000379:methods; D012756:Sheep; D014057:Tomography, X-Ray Computed / Q000379:methods; D014059:Tongue / Q000000981:diagnostic imaging / Q000473:pathology; D014070:Tooth; D014463:Ultrasonography; D014934:Wood
chemical_list: D008670:Metals; D010969:Plastics; D006108:Graphite
keywords: foreign body; imaging technique; maxillofacial region; visibility