Visualization of endolymphatic hydrops with MR imaging in patients with Ménière’s disease and related pathologies: current status of its methods and clinical significance

Abstract

Ménière's disease is an inner ear disorder characterized by vertigo attacks, fluctuating low-frequency hearing loss, ear fullness, and tinnitus. Endolymphatic hydrops has long been thought to be the pathological basis for Ménière's disease. Some patients have inner ear symptoms that do not match the diagnostic guidelines for Ménière's disease, and these are also thought to be related to endolymphatic hydrops. The diagnosis of endolymphatic hydrops is usually made based on clinical symptoms with some assistance from otological functional tests. Recently, the objective diagnosis of endolymphatic hydrops by MR imaging has become possible and many research results have been reported regarding the imaging methods, evaluation methods, the correlation between imaging results and functional otological tests and the correlation between imaging findings and clinical symptoms. In this article we summarize the development of current imaging methods, evaluation techniques and clinical reports based on a review of the literature. We also attempt to characterize the current significance and future directions of MR imaging of endolymphatic hydrops.

Endolymphatic Hydrops Reversal following Acetazolamide Therapy: Demonstration with Delayed Intravenous Contrast-Enhanced 3D-FLAIR MRI

“…The ability to visualize hydrops with this technique has been confirmed by multiple groups on different continents. [6][7][8]13 To date, however, no strong clinical application has been established for this technique, and existing research is mostly limited to showing a connection between a clinical diagnosis of MD and imaging evidence of hydrops.…”

Validity and Reliability of the Diagnostic Tests for Ménière's Disease

“…The presence of EH can be demonstrated in vivo with suppressed or disappeared signal intensity of the perilymphatic space in the Three-Dimensional Fluid Attenuated Inversion Recovery (3D FLAIR) sequences obtained from 3-Tesla MR that is performed 24 hours after intratympanic gadolinium injection. After intratympanic injection of gadolinium, Gd first reaches to the vestibule, passes through the basal turn of the cochlea, travels the semicircular canals, and finally arrives at the apical region of the cochlea (54,55). In patients with EH, perilymphatic space surrounding the endolymph is collapsed and sometimes invisible due to enlarged endolymphatic space.…”

“…This method is more sensitive than conventional MRI for EH in the cochlea or in the vestibule because it allows performing quantitative analysis and an objective comparison with the contralateral ear. It is believed that both intratympanic and intravenous application of gadolinium have similar diagnostic utility in viewing EH (55).…”

Vasopressin induces endolymphatic hydrops in mouse inner ear, as evaluated with repeated 9.4 T MRI

“…Thus, experimental and clinical MRI investigations of the inner ear have established that, when administered intravenously or intratympanically, the Gd complex readily penetrates the perilymphatic space, but not the endolymphatic space of the entire vestibulo-cochlea membranous labyrinth [Naganawa et al, 2012, Counter et al, 1999, Counter et al, 2000, Duan et al, 2004. Indeed, MRI in combination with Gd contrast agents has been used to visualize EH in patients with Ménière's disease [Naganawa et al, 2014, Zou et al, 2009, Baráth et al, 2014, Jerin et al, 2014 and in animal models developed to simulate human inner ear disease , Niyazov et al, 2001.…”