3D-real IR MRI of Meniere's disease with partial endolymphatic hydrops

MRI can help differentiate Ménière's disease from other menieriform diseases

It is difficult to distinguish other pathologies mimicking Ménière's disease (MD) clinically. This study aims to investigate the differences of imaging findings and features between MD and other menieriform diseases via intravenous gadolinium-enhanced magnetic resonance imaging (MRI). 426 patients with menieriform symptoms, including MD, vestibular migraine (VM), and vestibular schwannoma (VS), underwent 3D-FLAIR and 3D-T2WI MRI 6 h after the intravenous gadolinium injection. MR images were analyzed for inner ear morphology, perilymphatic enhancement (PE), EH and other abnormalities. EH was observed at a higher rate in MD patients (85.71%) than patients with other menieriform diseases (VM group = 14.75%, VS group = 37.50%). The prevalence of unilateral EH as well as both cochlear and vestibular EH showed significant differences between MD and VM groups. The prevalence of cochlear EH (I and II) and vestibular EH (II and III) was different between MD and VM groups. The prevalence of PE was higher in MD than VM group. The degrees of cochlear and vestibular hydrops were higher in the definite than probable MD group (P < 0.05). Using these imaging features, MRI can be used to help differentiate MD from other menieriform diseases.

Correlation Between Quantitative Value of Endolymphatic Hydrops and Hearing Threshold Using Magnetic Resonance Imaging

OBJECTIVES

This study investigated the relationship between quantitative value of endolymphatic hydrops in the affected ear and the hearing threshold in patients with unilateral Meniere's disease.

STUDY DESIGN

Prospective study.

METHODS

Forty patients with unilateral definite Meniere's disease were diagnosed in outpatient clinic. We recorded their clinical symptoms (duration of vertigo and tinnitus and duration of vertigo attacks), and obtained the hearing thresholds of high, middle, and low by pure tone audiometry. A 3D-FLAIR MRI revealed endolymphatic hydrops and assessed quantitative values of cochlear and vestibular endolymphatic hydrops. We assessed the correlation between hearing thresholds and quantitative values of endolymphatic hydrops.

RESULTS

All patients showed varying degrees of endolymphatic hydrops in the affected ear. With the duration of vertigo, tinnitus and vertigo attacks as control variables, partial correlation analysis showed that the correlation coefficients between quantitative value of cochlear hydrops and hearing thresholds of low, middle, and high tone in the affected ear were 0.581, 0.610, and 0.125, respectively. The correlation coefficients between quantitative value of vestibular hydrops and hearing thresholds of low, middle, and high tone in the affected ear were 0.727, 0.569, and 0.201, respectively.

CONCLUSIONS

The degree of endolymphatic hydrops in Meniere's disease can be revealed and assessed by 3D-FLAIR MRI after intravenous administration of double doses of gadoterate meglumine. Clinical evaluation of endolymphatic hydrops in Meniere's disease can be assisted by low- and middle-tone hearing thresholds, thereby providing anatomical support for the clinical symptoms of Meniere's disease.

Improving diagnostic accuracy for probable and definite Ménière's disease using magnetic resonance imaging

PURPOSE

To determine whether magnetic resonance imaging (MRI) can improve diagnostic accuracy for definite and probable Ménière's disease (MD) based on perilymphatic enhancement (PE) and endolymphatic hydrops (EH).

METHODS

363 patients with unilateral MD (probable MD, n = 75 and definite MD, n = 288) were recruited. A three-dimensional zoomed imaging technique with parallel transmission SPACE real inversion recovery was performed 6 h after intravenous gadolinium injection to investigate the presence of PE and to evaluate the grading and location of EH. PE and EH characteristics were analyzed and compared between the probable and definite MD groups.

RESULTS

The cochlear and vestibular EH grading on the affected side was more severe in the definite MD group than that in the probable MD group (P < 0.001). The EH locations within the inner ear on the affected side also differed between the two groups (χ2 = 81.15, P < 0.001). The signal intensity ratio (SIR) on the affected side was significantly higher in the definite MD group than in the probable MD group (t = 2.18, P < 0.05). The assessment of the combination of PE and EH parameters within the inner ear revealed a higher area under the curve (AUC) in the definite MD group (0.82) compared with the AUCs of the parameters assessed alone.

CONCLUSION

The assessment of a combination of PE and EH parameters improved the diagnostic accuracy for probable and definite MD, suggesting that MRI findings may be clinically useful in the diagnosis of MD.

Reliability of Endolymphatic Hydrops Qualitative Assessment in Magnetic Resonance Imaging

The study aimed to compare the consistency of MRI interpretation of endolymphatic hydrops qualitative assessment of inner ear structures performed by independent observers. MRI with a delayed post-contrast 3D-FLAIR sequence was performed to visualize EH in patients suspected of having or diagnosed with MD. The scans were analyzed independently by three observers. In total, 220 ears were evaluated and, of these, 75 had definite MD, five probable MD, 67 with other Menieriform symptoms, and 73 were asymptomatic. Significant differences in cochlear endolymphatic hydrops (CoEH) grading between all observers were observed. On the Barath scale of vestibular endolymphatic hydrops (VEH), differences were found between the radiologists and otorhinolaryngologist in grading. No differences were noted in VEH on the Bernaerts scale and increased perilymphatic enhancement. Our study showed that evaluation of vestibular endolymphatic hydrops is repeatable between observers and easy to learn. It proved that Bernaerts' modification increased the sensitivity of EH diagnosis. Both parameters, CoEH and VEH, may serve as a differentiation method of EH from normal ears. The distinction between normal and hydropic ears is much easier to perform than EH grading. Therefore, it may be used to diagnose MD rather than EH staging.

Consensus on MR Imaging of Endolymphatic Hydrops in Patients With Suspected Hydropic Ear Disease (Meniere)

Endolymphatic hydrops (EH) is considered the histological hallmark of Meniere's disease. Visualization of EH has been achieved by special sequences of inner ear magnetic resonance imaging (MRI) with a gadolinium-based contrast agent via intravenous or intratympanic administration. Although it has been applied for more than 10 years since 2007, a unified view on this technique has not yet been achieved. This paper presents an expert consensus on MRI of endolymphatic hydrops in the following aspects: indications and contra-indications for patient selection, methods of contrast-agent administration (intravenous or intratympanic), MRI sequence selection, the specific scanning parameter settings, and standard image evaluation methods and their advantages and disadvantages. For each part of this consensus, a comment is attached to elucidate the reasons for the recommendation.

Hydropic Ear Disease: Correlation Between Audiovestibular Symptoms, Endolymphatic Hydrops and Blood-Labyrinth Barrier Impairment

Research Objective: To investigate the correlation between clinical features and MRI-confirmed endolymphatic hydrops (EH) and blood-labyrinth barrier (BLB) impairment. Study Design: Retrospective cross-sectional study. Setting: Vertigo referral center (Haga Teaching Hospital, The Hague, the Netherlands). Methods: We retrospectively analyzed all patients that underwent 4 h-delayed Gd-enhanced 3D FLAIR MRI at our institution from February 2017 to March 2019. Perilymphatic enhancement and the degree of cochlear and vestibular hydrops were assessed. The signal intensity ratio (SIR) was calculated by region of interest analysis. Correlations between MRI findings and clinical features were evaluated. Results: Two hundred and fifteen patients with MRI-proven endolymphatic hydrops (EH) were included (179 unilateral, 36 bilateral) with a mean age of 55.9 yrs and median disease duration of 4.3 yrs. Hydrops grade is significantly correlated with disease duration (P < 0.001), the severity of low- and high-frequency hearing loss (both P < 0.001), and the incidence of drop attacks (P = 0.001). Visually increased perilymphatic enhancement was present in 157 (87.7%) subjects with unilateral EH. SIR increases in correlation with hydrops grade (P < 0.001), but is not significantly correlated with the low or high Fletcher index (P = 0.344 and P = 0.178 respectively). No significant differences were found between the degree of EH or BLB impairment and vertigo, tinnitus or aural fullness. Conclusion: The degree of EH positively correlates with disease duration, hearing loss and the incidence of drop attacks. The BLB is impaired in association with EH grade, but without clear contribution to the severity of audiovestibular symptoms.

Optimal sequences and sequence parameters for GBCA-enhanced MRI of the glymphatic system: a systematic literature review

BACKGROUND

The glymphatic system (GS) is a recently discovered waste clearance system in the brain.

PURPOSE

To evaluate the most promising magnetic resonance imaging (MRI) sequence(s) and the most optimal sequence parameters for glymphatic MRI (gMRI) 4-24 h after administration of gadolinium-based contrast agent (GBCA).

MATERIAL AND METHODS

Multiple literature databases were systematically searched for articles regarding gMRI or MRI of the perilymph in the inner ear until 11 May 2020. All relevant MRI sequence parameters were tabulated for qualitative analysis. Their potential was assessed based on detection of low dose GBCA, primarily measured as signal intensity (SI) ratio.

RESULTS

Thirty articles were included in the analysis. Three-dimensional fluid attenuated inversion recovery (3D-FLAIR), 3D Real Inversion Recovery (3D-Real IR), and multiple 3D T1-weighted gradient echo sequences were used. In perilymph, 3D-FLAIR with a TE of at least 400 ms yielded the highest SIRs. In the qualitative analysis of inner ear studies using 3D-FLAIR, TR was in the range of 4400-10,000 ms, TI 1500-2600 ms, refocusing flip angle (rFA) (range 120°-180°), and echo train length (ETL) 23-173. In the gMRI studies, quantitative analysis was not possible. In the qualitative analysis, 3D-FLAIR was used in the majority (8/12) of the studies, usually with TR 4800-9000 ms, TI 1650-2500 ms, TE 311-561 ms, rFA 90°-120°, and ETL 167-278.

CONCLUSION

Long TE 3D-FLAIR is the most promising sequence for detection of low-dose GBCA in the GS. Clinical and/or phantom studies on other MRI parameters are needed for further optimization of gMRI.

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

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.

State of the Art Imaging in Menière’s Disease. Tips and Tricks for Protocol and Interpretation

Purpose of Review

Menière’s disease (MD) is a burdensome and not well understood inner ear disorder that has received increasing attention of scientists over the past decade. Until 2007, a certain diagnosis of endolymphatic hydrops (EH) required post-mortem histology. Today, dedicated high-resolution magnetic resonance imaging (MRI) protocols enable detection of disease-related changes in the membranous labyrinth in vivo. In this review, we summarize the current status of MR imaging for MD.

Recent Findings

The mainstays of hydrops imaging are inversion recovery sequences using delayed acquisition after intravenous or intratympanic contrast administration. Based on these techniques, several methods have been developed to detect and classify EH. In addition, novel imaging features of MD, such as blood-labyrinth barrier impairment, have recently been observed.

Summary

Delayed contrast enhanced MRI has emerged as a reliable technique to demonstrate EH in vivo, with promising application in the diagnosis and follow-up of MD patients. Therefore, familiarity with current techniques and diagnostic imaging criteria is increasingly important.

MR imaging and clinical characteristics of Lermoyez syndrome

Background: Lermoyez syndrome (LS) is a rare auditory disorder, the details of LS remain unclear.Objectives: To investigate the grades of endolymphatic hydrops (ELH) and clinical characteristics of clinically diagnosed LS.Material and methods: Nine patients with clinically diagnosed LS were included. three-dimensional-real-infra red imaging characteristics were analyzed. ELH grades and detailed clinical characteristics were evaluated.Results: The group consisted of two women and seven men with an age at presentation of 48.4 ± 10.9 (28-61) years, an onset age of 40.9 ± 12.0 (23-58) years, and a disease duration of 7.6 ± 7.5 years. Of the nine patients, ELH was observed in 100% of the patients on the clinically affected side. In addition, 22.2% of vestibular ELH and 77.8% of cochlear ELH were classified as mild or moderate in grade.Conclusions and significance: The patients with LS had Meniere's triad, fluctuation of hearing that occurred in a reverse relationship to that of the vertiginous attack, and vestibular and cochlear ELH, which may suggest that LS is a variant of MD. However, the sex difference and milder cochlear ELH in LS compared with those in typical MD may indicate an underlying intrinsic difference in the mechanism of LS.

Value of Endolymphatic Hydrops and Perilymph Signal Intensity in Suspected Ménière Disease

BACKGROUND AND PURPOSE

Ménière disease is characterized by endolymphatic hydrops, whereas perilymphatic enhancement on MR imaging has been suggested to be of additional value in diagnosing Ménière disease. This study evaluates the presence of endolymphatic hydrops and perilymphatic enhancement in patients with Ménière disease and with other vertigo-associated inner ear pathology.

MATERIALS AND METHODS

A 3D-FLAIR sequence 4 hours after intravenous gadolinium injection was performed to visualize the endolymph and perilymph in 220 patients suspected of having Ménière disease. Patients' ears were retrospectively categorized as having Ménière disease (probable or definite) or other vertigo-associated inner ear pathology not attributable to Ménière disease. Endolymphatic hydrops was evaluated using a visual classification system, and perilymphatic enhancement was scored both visually and quantitatively.

RESULTS

Endolymphatic hydrops was present in 137 (91.9%) of the definite Ménière disease ears and in 9 (7.0%) of the ears with other vertigo-associated inner ear pathology (P < .001). The combination of endolymphatic hydrops and visually increased perilymphatic enhancement was present in 122 (81.9%) definite Ménière disease ears compared with 4 (3.1%) ears with other vertigo-associated inner ear pathology (P < .001). This combination increases the positive predictive value from 0.94 for endolymphatic hydrops and 0.91 for perilymphatic enhancement to 0.97. The addition of measured perilymphatic enhancement leads to a moderate decrease in sensitivity from 0.92 for endolymphatic hydrops to 0.86.

CONCLUSIONS

The combination of perilymphatic enhancement and endolymphatic hydrops in patients suspected of having Ménière disease increases the positive predictive value in the diagnosis of definite Ménière disease.