Computed tomography and otosclerosis: a practical method to correlate the sites affected to hearing loss

Ann Otol Rhinol Laryngol. 2010 Dec;119(12):789-94. doi: 10.1177/000348941011901201.


Objectives: We present a practical method for correlating computed tomography (CT) scans with hearing loss in otosclerosis.

Methods: We reviewed the CT scans of 18 patients (34 ears) with clinical otosclerosis who were seen between 2007 and 2008. The scans were reviewed by an otologist in a clinical office setting, followed by a blinded radiologist working at an imaging workstation. The 5 most commonly affected sites in otosclerosis were evaluated for evidence of otospongiosis and then correlated with the degree of air-bone gap and sensorineural hearing loss.

Results: Positive CT findings were noted in 70.5% of ears, with a 94% concordance between readings. The sites affected included the ante fenestram (21 ears), round window niche (12), cochlear promontory (4), cochlear apex (3), and posterior fenestram (2). The average air-bone gap increased with each additional site of involvement within an otic capsule (p = 0.004). The bone conduction threshold also increased, on average, with each additional affected site (p = 0.047).

Conclusions: Most patients with clinical evidence of otosclerosis have evidence of otosclerosis on CT that is readily detected in the office setting. Ears with more affected sites have a significantly greater degree of air-bone gap and sensorineural hearing loss.

MeSH terms

  • Adult
  • Audiometry, Pure-Tone
  • Ear, Inner / diagnostic imaging*
  • Female
  • Hearing Loss, Conductive / diagnosis
  • Hearing Loss, Conductive / etiology
  • Hearing Loss, Mixed Conductive-Sensorineural / diagnosis
  • Hearing Loss, Mixed Conductive-Sensorineural / etiology
  • Hearing Loss, Sensorineural / diagnosis
  • Hearing Loss, Sensorineural / etiology
  • Humans
  • Male
  • Middle Aged
  • Otosclerosis / complications
  • Otosclerosis / diagnostic imaging*
  • Temporal Bone / diagnostic imaging
  • Tomography, X-Ray Computed*
  • Young Adult