Clinical value of abnormal MRI findings in patients with unilateral sudden sensorineural hearing loss

We aimed to determine the relationship of abnormal labyrinthine signals on heavily T2-weighted three-dimensional fluid-attenuated inversion recovery imaging (HF sequence) with hearing impairment and prognosis in patients with sudden sensorineural hearing loss (SSNHL).

Patients with unilateral SSNHL underwent magnetic resonance imaging, including pre-contrast HF sequences and post-contrast HF sequences with a 4-hour scan delay after intravenous gadolinium injection. We measured the signal intensity ratio (SIR) of the vestibule and cochlea relative to the cerebellar medulla on post-contrast HF sequences, and analyzed the relationship of SIR with hearing impairment and prognosis.

Of 61 patients, 23 (37.7%) showed signal abnormalities on post-contrast HF sequences. Initial hearing loss and hearing recovery were worse in the HF+ group than in the HF- group (P < 0.05). Profound hearing loss was more common in the HF+ group (52.2% vs. 23.7%), while moderate hearing loss was more common in the HF- group (18.4% vs. 0.0%; P < 0.05 for both). The rate of partial recovery was higher in the HF- group (42.1%) than in the HF+ group (13.0%; P < 0.05). The SIRs of the vestibule and cochlea were positively correlated with the severity of hearing loss and hearing recovery, with higher SIRs indicating more severe hearing loss and poor recovery.

Labyrinthine signal abnormalities were found on post-contrast HF sequences in 37.7% of patients with SSNHL. These abnormalities were found only in patients with severe-to-profound hearing loss. Increased SIR indicated more severe hearing loss and poor prognosis.