title: Three-dimensional computed tomography imaging in the sitting position for the diagnosis of patulous eustachian tube.
abstract: OBJECTIVE
  Computed tomography (CT) in the sitting position was useful for detecting patulous Eustachian tube (ET).
  
  
  METHODS
  Retrospective.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  Eighty-seven patients divided into two groups. The patulous ET group consisted of 111 ears of 67 patients with patulous ET. The control group consisted of 30 ears of 20 patients without symptoms characteristic of patulous ET or abnormal findings in ET function tests.
  
  
  METHODS
  CT was performed under the resting condition and during Valsalva maneuver (Valsalva condition). The multiplanar reconstruction technique was used to reconstruct 1-mm-thick gapless images parallel to and perpendicular to the ET long axis. The open tubal distance (OTD) and average ET-gram were examined.
  
  
  RESULTS
  The OTD was significantly longer in the patulous ET group than in the control group under both resting and Valsalva conditions (both p < 0.001). The OTD was also significantly longer under the Valsalva condition than under the resting condition in both groups (p < 0.01 in the patulous ET group, p < 0.001 in the control group). The average ET-gram showed an occlusive zone in the cartilaginous portion medial to the isthmus under both the resting and Valsalva conditions in the control group (n = 30). However, the occlusive zone could not be observed under either the resting or Valsalva conditions in the patulous ET group (n = 111). Completely patent (open) ET was observed with continuous hyperlucency from the pharyngeal to the tympanic orifices in 88 of 111 patients in the patulous ET group, but in none of the control group, indicative of 100% specificity.
  
  
  CONCLUSIONS
  Computed tomography in the sitting position employing Valsalva maneuver is useful for the diagnosis of patulous ET.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan. toshi330@orl.med.tohoku.ac.jp
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Kikuchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Oshima
authors.forename: Masaki
authors.initials: M
authors.lastname: Ogura
authors.forename: Yoko
authors.initials: Y
authors.lastname: Hori
authors.forename: Tetsuaki
authors.initials: T
authors.lastname: Kawase
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Kobayashi
mesh_terms: D000328:Adult; D004427:Ear Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging*; D005064:Eustachian Tube / Q000000981:diagnostic imaging* / Q000502:physiology; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D011187:Posture; D011859:Radiography; D012189:Retrospective Studies; D014636:Valsalva Maneuver