Magnetic resonance imaging findings in Ménière's disease: the impact of radiologist experience on hydrops imaging.

Purpose: This study investigates the competence of a newly certified radiologist in reporting hydrops imaging and examines the role of magnetic resonance imaging (MRI) findings in diagnosing definite and probable Ménière's disease (MD).

Methods: Sixty-four cases were retrospectively evaluated-blinded to clinical data-by a senior radiologist (O-1) and a newly certified radiologist (O-2) using 3D heavily T2-weighted and delayed contrast-enhanced three-dimensional fluid-attenuated inversion recovery sequences. The posterior fossa-posterior semicircular canal (P-P) distance, endolymphatic hydrops (EH), perilymphatic enhancement (PE), and the round window sign (RWS) were assessed.

Results: Interobserver agreement was moderate for cochlear (κ = 0.591) and vestibular hydrops (κ = 0.566), good for PE (κ = 0.663), and excellent for the RWS (κ = 0.817). O-1 demonstrated good intraobserver agreement for the RWS (κ = 0.787) and excellent agreement for the other parameters. O-2 showed lower intraobserver agreement for cochlear hydrops, vestibular hydrops, and the RWS (κ = 0.366, κ = 0.332, and κ = 0.398, respectively). The P-P distance showed excellent interobserver [intraclass correlation coefficient (ICC) = 0.932] and intraobserver agreement (ICC = 0.978 for O-1; ICC = 0.886 for O-2). The P-P distance was significantly shorter in definite MD (dMD) than in probable MD (pMD) (1.23 ± 1.07 mm vs. 2.17 ± 1.79 mm, P = 0.021). The rate and grade of hydrops were higher in dMD (P < 0.050), whereas the RWS was more frequent in pMD. Hydrops and PE were more often observed on the symptomatic side (P < 0.001). Cochlear hydrops was identified in 14.3% and vestibular hydrops in 31.2% of asymptomatic sides.

Conclusion: The newly certified radiologist's intraobserver agreement for hydrops imaging was insufficient. In dMD, the retrolabyrinthine bone is thinner, hydrops is more frequent and advanced, and the RWS is less common. Approximately one in five patients with MD may have a perilymphatic fistula. Close monitoring of asymptomatic contralateral ears is essential.

Clinical significance: Accurate MRI evaluation of EH in MD strongly depends on the radiologist's expertise. This study highlights that newly certified radiologists may show lower reliability in assessing hydrops imaging, underscoring the need for targeted training programs.