Magnetic resonance imaging of the internal auditory meatus for vestibular schwannoma in ENT practice: a retrospective analysis with literature and guidelines review

Magnetic resonance imaging scans of the internal acoustic meatus are commonly requested in the investigation of audio-vestibular symptoms for potential vestibular schwannoma. There have been multiple studies into protocols for requesting magnetic resonance imaging for vestibular schwannoma, but none have been reported based on UK National Institute for Health and Care Excellence guidelines for investigating audio-vestibular symptoms. This study intended to identify the local magnetic resonance imaging detection rates and patterns of vestibular schwannoma, and to audit the conformity of scan requests with the National Institute for Health and Care Excellence guidelines, with a review of relevant literature.A retrospective analysis of 1300 magnetic resonance imaging scans of the internal acoustic meatus, compared against National Institute for Health and Care Excellence guidelines, was conducted over two years.Sixteen scans were positive for vestibular schwannoma, with a detection rate of 1.23 per cent. All positive cases fit the guidelines; three of these could have been missed using other criteria. A total of 281 requests did not meet the guideline criteria but revealed no positive results, supporting the use of National Institute for Health and Care Excellence guidelines in planning magnetic resonance imaging scans for audio-vestibular symptoms.