Advanced Imaging of the Vestibular Endolymphatic Space in Ménière's Disease

Abstract

The diagnosis of “definite” Méniére's disease (MD) relies upon its clinical manifestations. MD has been related with Endolymphatic Hydrops (EH), an enlargement of the endolymphatic spaces (ES) (cochlear duct, posterior labyrinth, or both). Recent advances in Magnetic Resonance (MR) imaging justify its increasing role in the diagnostic workup: EH can be consistently recognized in living human subjects by means of 3-dimensional Fluid-Attenuated Inversion-Recovery sequences (3D-FLAIR) acquired 4 h post-injection of intra-venous (i.v.) Gadolinium-based contrast medium, or 24 h after an intratympanic (i.t.) injection. Different criteria to assess EH include: the comparison of the area of the vestibular ES with the whole vestibule on an axial section; the saccule-to-utricle ratio (“SURI”); and the bulging of the vestibular organs toward the inferior 1/3 of the vestibule, in contact with the stapedial platina (“VESCO”). An absolute link between MD and EH has been questioned, since not all patients with hydrops manifest MD symptoms. In this literature review, we report the technical refinements of the imaging methods proposed with either i.t. or i.v. delivery routes, and we browse the outcomes of MR imaging of the ES in both MD and non-MD patients. Finally, we summarize the following imaging findings observed by different researchers: blood-labyrinthine-barrier (BLB) breakdown, the extent and grading of EH, its correlation with clinical symptoms, otoneurological tests, and stage and progression of the disease.

Ménière's disease: new guidelines, subtypes, imaging, and more

“…Recently developed MRI protocols and techniques allow for endolymphatic hydrops to be consistently recognized in living human subjects with MRI [41]. The technique involves three-dimensional fluidattenuated inversion recovery (FLAIR) sequences performed at 4 h postintravenous gadolinium [41,42]. There are several imaging criteria used to assess endolymphatic hydrops and include: the comparison of the area of the vestibular endolymphatic spaces, the saccule-to-utricle ratio, and the bulging of the vestibular organs toward the inferior one-third of the vestibule [41].…”

“…The technique involves three-dimensional fluidattenuated inversion recovery (FLAIR) sequences performed at 4 h postintravenous gadolinium [41,42]. There are several imaging criteria used to assess endolymphatic hydrops and include: the comparison of the area of the vestibular endolymphatic spaces, the saccule-to-utricle ratio, and the bulging of the vestibular organs toward the inferior one-third of the vestibule [41]. Unfortunately, 3 Tesla MRIs (required to adequately see endolymphatic hydrops) are not widely available, generally limiting its implementation to larger academic settings.…”

“…[27 ▪▪ ]. Recently developed MRI protocols and techniques allow for endolymphatic hydrops to be consistently recognized in living human subjects with MRI [41]. The technique involves three-dimensional fluid-attenuated inversion recovery (FLAIR) sequences performed at 4 h postintravenous gadolinium [41,42].…”

The diagnostic performance of Cochlear Endolymphatic Hydrops and Perilymphatic Enhancement in Stratifying Ménière's Disease probabilities: A Meta-Analysis of semi-quantitative MRI-based grading systems

“…The inconsistency in grading systems underscores a signi cant hurdle in achieving consensus on diagnostic criteria, complicating the interpretation and comparability of research ndings [6]. The literature has seen various attempts [7][8][9][10][11][12] to consolidate MRI-based evaluations of EH in MD, with Connor et al [12]'s meta-analysis standing out as a seminal work that navigated through the complexities of diagnostic performance with a quantitative lens.…”

Delayed post gadolinium MRI descriptors for Meniere’s disease: a systematic review and meta-analysis

“…The reporting of EH on MRI is generally based on the evaluation of descriptors and semi-quantitative grading scales [ 19 , 22 , 24 , 31 , 46 , 79 , 94 – 97 ] but there is little consensus on which of these perform best in distinguishing affected ears. Despite previous systematic reviews on the subject [ 89 – 93 ], there have been no attempts to determine the pooled diagnostic performance of MRI descriptors. Meta-analysis would provide greater certainty as to how MRI should be interpreted to optimally corroborate the diagnosis of MD.…”