Magnetic resonance imaging scans for vestibulocochlear nerve tumours: what is actually found?

Background: Approximately 20 per cent of adult patients presenting to otolaryngology clinics have symptoms pertaining to the inner ear. These are investigated with magnetic resonance imaging (MRI) internal auditory meatus scans. This study analysed all findings from 736 sequential MRI internal auditory meatus scans performed on 731 patients over a one year period. Methods: Six hundred and seventy-two patients were included for analysis. Of these, 419 (62.35 per cent) had normal MRI scans, 221 (32.90 per cent) had MRI findings thought to be unrelated to their presenting symptoms, 32 (4.76 per cent) had findings thought to be the cause of their symptoms, and eight (1.19 per cent) had the typical appearance of an VIIIth nerve schwannoma. Conclusions: Magnetic resonance image scanning of the inner ears and auditory pathways yields a diagnosis of VIIIth nerve tumours of the order of 1 per cent, does not show other causes of inner-ear symptoms in a further 4 per cent, and shows incidental intra- and extracranial abnormalities in a further 33 per cent, most of which are not clinically significant.