Utility of MRI quantitative analysis in assessment of audio-vestibular impairment

Objectives. To quantify inner ear fluid changes in patients with audiovestibular deficits by measuring signal intensity values; to correlate the signal intensity values of inner ear structures and audio-vestibular impairment severity. Methods. 26 patients with unilateral vestibulocochlear deficits underwent hearing and vestibular assessments and were categorised into severity classes using audiological and vestibular deficit scores. Normalised signal intensity values of inner ear structures were extracted from 3D-T2WI-MRI scans (nT2mean, nT2Max, nT2min) and signal intensity ratios were calculated using the unaffected ear as a reference. Results. Asymmetry ratios of nT2Max and nT2mean volumetric intensity values from the cochlea and entire inner ear discriminated severe hearing impairment from lesser deficits and diagnostic performance of nT2mean values was excellent. Conclusions. Quantitative MRI analysis may be a useful tool to assess the severity of auditory deficits. Asymmetry ratios of nT2mean and nT2Max signal intensity values derived from the cochlea and entire inner labyrinth are surrogate indicators of unilateral cochlear-vestibular deficits and may have potential prognostic value.