The purpose of this study was to assess whether the volume of the vestibular endolymphatic space correlates with the degree of hearing loss using heavily T2-weighted fast imaging employing steady-state acquisition with cycle phase (FIESTA-C) MRI.

A total of 23 patients with vestibular schwannoma, as diagnosed on typical image findings, who underwent FIESTA-C MRI were included. There were 13 women and 10 men with a mean age of 63.5±9.3 (SD) years (range: 49–88years). Two radiologists independently evaluated the volume of the utricle and saccule. Correlation between tumor volume, vestibular endolymphatic space volume and degree of hearing loss – as evaluated with the levels of pure-tone average and speech recognition threshold – were searched for.

The mean saccular, utricular and tumor volumes were 3.17±1.1 (SD) mm³ (range: 1.45–5.7mm³), 14.55±5 (SD) mm³; (range: 6.6–23.9mm³) and 17.4±5.5 (SD) mm³; (range: 8.3–25.4mm³), respectively. There was a moderate correlation between the volume of the utricle and the degree of hearing loss as evaluated with the levels of pure-tone average (rho=0.5; P=0.015) and speech recognition threshold (rho=0.58; P=0.004). There were no significant correlations between saccular and tumor volumes and the degree of hearing loss.

The volume of the utricle in patients with obstructive vestibular schwannoma moderately correlates with the degree of hearing loss.