Lesion-specific prognosis by magnetic resonance imaging in sudden sensorineural hearing loss

Abstract

Background High signals in the inner ear of idiopathic sudden sensorineural hearing loss (ISSNHL) on magnetic resonance imaging (MRI) have been reported, but no quantitative evaluation has yet been done. Objectives To evaluate hearing outcomes and cochlear signal intensities on 3-T heavily T2-weighted three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (hT2W-3D-FLAIR) in patients with ISSNHL. Materials and methods Twenty-nine patients with ISSNHL were included. Patients underwent hT2W-3D-FLAIR with intravenous gadolinium injection and pure tone audiometry (PTA) at initial visits and 3 months later. Signal intensity ratios (SIRs) were measured in the basal or apical-middle turns of the affected cochlea. A statistical analysis of relationships between SIRs and the average hearing levels (HLs) at low (125, 250, and 500 Hz) and high (2, 4, and 8 kHz) tone frequencies was performed. Results Hearing improvements at high-tone frequencies in ears with HLs ≥60 dB were significantly worse in those with high SIRs at the basal turns on pre-contrast images. Similarly, hearing improvements at low-tone frequencies in ears with HLs ≥60 dB were significantly worse in those with high SIRs at the apical-middle turns on post-contrast images. Conclusions and significance High SIRs on hT2W-3D-FLAIR indicate cochlear disturbances with severe ISSNHL and could provide lesion-specific prognostic information.