title: Temporal bone imaging in osteogenesis imperfecta patients with hearing loss.
abstract: OBJECTIVE
  Osteogenesis imperfecta (OI) is an autosomal-dominant connective-tissue disorder, predominantly characterized by bone fragility. Conductive hearing loss develops in half of the OI patients and often progresses to mixed loss. Findings of computed tomography (CT) and magnetic resonance (MR) imaging of the temporal bone in the largest series of OI patients to date are presented and correlated with the audiograms.
  
  
  METHODS
  Retrospective case series.
  
  
  METHODS
  CT images and audiograms of 17 hearing-impaired OI patients, aged 9 to 67 years, were analyzed retrospectively. In four patients, MR imaging was performed as well. Imaging abnormalities were correlated with type and severity of hearing loss deduced from the audiograms.
  
  
  RESULTS
  CT revealed fenestral hypodense foci in the fissula ante fenestram (25 of 33 ears), oval window (23 of 33 ears), and round window (20 of 33 ears). Retrofenestral hypodensities were observed, affecting the cochlear turns (16 of 33 ears), facial nerve canal (10 of 33 ears), or semicircular canals (6 of 33 ears), or appearing like the fourth turn of the cochlea (11 of 33 ears). The site of hypodensities corresponded to the type of hearing loss in 72.2% of the OI ears. The air-bone gap and bone-conduction thresholds showed significant positive associations with the number of affected fenestral (P < .05) and retrofenestral structures (P < .01), respectively. Gadolinium-enhanced MR images demonstrated active lesions in three patients with mixed hearing loss or deafness.
  
  
  CONCLUSIONS
  The site of hypodensities on temporal bone CT images in OI corresponds to presence and type of hearing loss determined by audiometry. The more severe the hearing loss, the more affected temporal bone structures in OI.
authors: Department of Otorhinolaryngology, Ghent University Hospital, Ghent, Belgium. freya.swinnen@UGent.be
authors: Freya K R
authors: FK
authors: Swinnen
authors: Jan W
authors: JW
authors: Casselman
authors: Els M R
authors: EM
authors: De Leenheer
authors: Cor W R J
authors: CW
authors: Cremers
authors: Ingeborg J M
authors: IJ
authors: Dhooge
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001299:Audiometry; D002648:Child; D005260:Female; D034381:Hearing Loss / Q000150:complications / Q000000981:diagnostic imaging*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010013:Osteogenesis Imperfecta / Q000150:complications / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D013701:Temporal Bone / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Osteogenesis imperfecta; computed tomography; magnetic resonance imaging; temporal bone