title: Anatomy of the bony portion of the eustachian tube in tubal stenosis: multiplanar reconstruction approach.
abstract: OBJECTIVE
  We sought to clarify possible pathological conditions of the bony portion of the eustachian tube (ET) in patients with ET stenosis.
  
  
  METHODS
  We measured the total length, the cross-sectional area of the bony frame, and the air space of the ET lumen at an interval of 1 mm on the reconstructed computed tomographic images of the ET using a multiplanar reconstruction method on 20 normal subjects (control group) and 25 patients with stenotic ET judged by the inflation test (stenotic group).
  
  
  RESULTS
  In the cross-sectional areas, both the bony frame and air space were significantly smaller in the stenotic group than in the control group. The soft tissue ratio was significantly greater in most parts of the mid-bony portion and the tympanic orifice of the stenotic group than in those of the control group. At the anterior tip of the bony portion, only the bony frame was found to be significantly smaller in the stenotic group than in the control group.
  
  
  CONCLUSIONS
  We suggest that a smaller framework of the bony ET may possibly be related to the pathogenesis of ET stenosis.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Haruo
authors.initials: H
authors.lastname: Yoshida
authors.forename: Haruo
authors.initials: H
authors.lastname: Takahashi
authors.forename: Minoru
authors.initials: M
authors.lastname: Morikawa
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Kobayashi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging; D004427:Ear Diseases / Q000000981:diagnostic imaging*; D005064:Eustachian Tube / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013701:Temporal Bone / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*