Endolymphatic volume in patients with meniere's disease and healthy controls: Three‐dimensional analysis with magnetic resonance imaging

OBJECTIVE: Recently, 3‐Tesla magnetic resonance imaging (MRI) with intravenous gadolinium injection has been used to reveal endolymphatic hydrops (EH). In the present study, we aimed to evaluate EH in patients with Meniere's disease (MD) objectively and quantitatively, and compared the endolymphatic space (ELS) in individuals with MD and healthy controls, to gain understanding of the characteristics of MD. METHODS: Eighty‐two patients with unilateral MD (uMD), 16 patients with bilateral MD (bMD), and 47 healthy volunteers were enrolled. All participants underwent 3‐T MRI at 4 hours after intravenous gadolinium injection. The volumes of the total fluid space (TFS) and ELS were measured semiautomatically using our workstation, and the percentage of ELS to TFS (ELS percentage) was calculated. RESULTS: The ELS percentage was 13.9 in the ears of controls, 18.2 in the contralateral ear of individuals with uMD, 26.1 in the affected ears of these individuals, and 23.0 in both ears of individuals with bMD. The ELS percentages in the affected ear of uMD and the ears of bMD individuals were significantly higher than that in the ears of control individuals (P < .01, one‐way analysis of variance (ANOVA), Tukey's test). CONCLUSION: The ELS is significantly larger in the affected ears of uMD and in both ears of bMD individuals. Accurate diagnosis of MD can be facilitated by using 3‐T MRI 4 hours after intravenous gadolinium injection and performing volumetric measurements of the ELS. LEVEL OF EVIDENCE: 2b