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

Abstract

Objectives: Delayed post-gadolinium magnetic resonance imaging (MRI) detects changes of endolymphatic hydrops (EH) within the inner ear in Meniere's disease (MD). A systematic review with meta-analysis was conducted to summarise the diagnostic performance of MRI descriptors across the range of MD clinical classifications.

Materials and methods: Case-controlled studies documenting the diagnostic performance of MRI descriptors in distinguishing MD ears from asymptomatic ears or ears with other audio-vestibular conditions were identified (MEDLINE, EMBASE, Web of Science, Scopus databases: updated 17/2/2022). Methodological quality was evaluated with Quality Assessment of Diagnostic Accuracy Studies version 2. Results were pooled using a bivariate random-effects model for evaluation of sensitivity, specificity and diagnostic odds ratio (DOR). Meta-regression evaluated sources of heterogeneity, and subgroup analysis for individual clinical classifications was performed.

Results: The meta-analysis included 66 unique studies and 3073 ears with MD (mean age 40.2-67.2 years), evaluating 11 MRI descriptors. The combination of increased perilymphatic enhancement (PLE) and EH (3 studies, 122 MD ears) achieved the highest sensitivity (87% (95% CI: 79.92%)) whilst maintaining high specificity (91% (95% CI: 85.95%)). The diagnostic performance of "high grade cochlear EH" and "any EH" descriptors did not significantly differ between monosymptomatic cochlear MD and the latest reference standard for definite MD (p = 0.3; p = 0.09). Potential sources of bias were case-controlled design, unblinded observers and variable reference standard, whilst differing MRI techniques introduced heterogeneity.

Conclusions: The combination of increased PLE and EH optimised sensitivity and specificity for MD, whilst some MRI descriptors also performed well in diagnosing monosymptomatic cochlear MD.

Key points: • A meta-analysis of delayed post-gadolinium magnetic resonance imaging (MRI) for the diagnosis of Meniere's disease is reported for the first time and comprised 66 studies (3073 ears). • Increased enhancement of the perilymphatic space of the inner ear is shown to be a key MRI feature for the diagnosis of Meniere's disease. • MRI diagnosis of Meniere's disease can be usefully applied across a range of clinical classifications including patients with cochlear symptoms alone.

Keywords: Ear, inner; Endolymphatic hydrops; Gadolinium; Magnetic resonance imaging; Odds ratio.

Fig. 1

Flow chart summary of the literature search and systematic review process

Fig. 2

Illustrations of the MRI descriptors. a T2 SPACE axial image is unable to distinguish the endolymphatic from the perilymphatic space and demonstrates the inner ear structures as high signal throughout. The cochlea (vertical arrow) and the vestibule (horizontal arrow) are indicated. b Delayed post-gadolinium 3D REAL IR axial image in a normal ear shows that the endolymphatic structures of the saccule (vertical arrow) and the utricle (horizontal arrow) demonstrated within the vestibule with the saccule being the smaller structure. The low signal endolymph is clearly distinguished from the surrounding enhancing perilymph. Schematic representations of (c) the normal endolymphatic structures and (d) the hydropic (dilated) endolymphatic structures in a MD ear (permission to use from Miss Irumee Pai). The lines depict the level of the axial sections which encompass the utricle (U) and saccule (S) in the other images Delayed post-gadolinium 3D REAL IR axial images in e to h depict the MR descriptors in ears with MD. e “Saccule to utricle ratio (SURI)”. There is inversion of the saccule to utricle ratio (SURI) with the saccule (vertical arrow) being larger than the utricle (horizontal arrow). f “Fused utricle and saccule”. The low-signal saccule and utricle are seen to be merged (horizontal arrow). There is also borderline “ > 33% area of ES relative to total vestibular fluid area” but it does not reach “ > 50% of ES relative to total vestibular fluid area”. g “Enhancing PS of the vestibule not visible “and “highest grade cochlear EH”. Severe EH is demonstrated with replacement of the vestibular perilymph by non enhancing endolymph (horizontal arrow) and there is also “ > 50% of ES relative to total vestibular fluid area”. There is severe cochlear hydrops (vertical arrows) as indicated by the non enhancing cochlear duct replacing the scala vestibuli enhancement (vertical arrows). h A right MD ear demonstrating “increased ipsilateral perilymphatic enhancement (PLE)”. The degree of perilymphatic enhancement within the inferior segment of the right basal turn (open arrow) is increased in the right symptomatic MD ear relative to the contralateral left asymptomatic ear (filled arrow)

Fig. 3

Bar charts demonstrate (a) the risk of bias and (b) applicability concerns derived from the QUADAS-2 tool for the 66 eligible studies included in the meta-analysis

Fig. 4

Forest plots with sensitivity and specificity for each MRI descriptor (a–k), incorporating all relevant reports and with pooled values

Fig. 4

Forest plots with sensitivity and specificity for each MRI descriptor (a–k), incorporating all relevant reports and with pooled values

Fig. 4

Forest plots with sensitivity and specificity for each MRI descriptor (a–k), incorporating all relevant reports and with pooled values

Fig. 4

Forest plots with sensitivity and specificity for each MRI descriptor (a–k), incorporating all relevant reports and with pooled values

Fig. 4

Forest plots with sensitivity and specificity for each MRI descriptor (a–k), incorporating all relevant reports and with pooled values

Fig. 4

Forest plots with sensitivity and specificity for each MRI descriptor (a–k), incorporating all relevant reports and with pooled values