The value of four stage vestibular hydrops grading and asymmetric perilymphatic enhancement in the diagnosis of Menière's disease on MRI

Comparison between high-resolution 3D-IR with real reconstruction and 3D-flair sequences in the assessment of endolymphatic hydrops in 3 tesla

BACKGROUND

The main sequences used to assess degree of endolymphatic hydrops (EH) are the 3D- inversion-recovery (IR) with real reconstruction and the 3D- fluid-attenuated inversion recovery (FLAIR).

OBJECTIVES

The purpose of this study is to describe and compare both sequences.

MATERIAL AND METHODS

Forty-two consecutive patients diagnosed with probable or definite Ménièr´s disease were referred for hydrops MR examination. Vestibular and cochlear EH in both sequences were read by two independent radiologists, unaware of the patient's clinical status. The primary study endpoint was the concordance in the hydrops detection and severity with both imaging sequences. This was assessed using the Cohen's kappa Κ statistic for disease grading and Pearson Χ² test to test the difference in detection rates of hydrops. Statistical significance was defined as two-sided p < .05.

RESULTS

We obtained an excellent overall concordance, with a kappa of 0.821, (p < .001) when comparing hydrops detection. The degree of concordance is higher in vestibular hydrops than in cochlear hydrops. The 3D-IR sequence detected more hydrops than the 3D FLAIR, (62 vs. 39.5%, p < .03).

CONCLUSION

The 3D-IR sequence seems to be superior to the 3D-FLAIR for the assessment of EH. Significance: The 3D-IR sequence should be considered as a standalone parameter for a shorter and optimized EH magnetic resonance imaging protocol.

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.

Endolymphatic hydrops magnetic resonance imaging in Ménière's disease

This review is designed to help radiologists interested in developing a magnetic resonance imaging service for patients with symptoms of Ménière's disease. Examples are selected from our experience with delayed post-gadolinium three-dimensional (3D) fluid attenuated inversion recovery (FLAIR) inner ear imaging of endolymphatic hydrops. The imaging features of the normal and hydropic endolymphatic structures, semiquantitative grading systems, normal variations, and differential diagnoses will be illustrated, whilst appropriate clinical referrals, approaches to reporting and diagnostic pitfalls will be discussed.

MR Imaging of Endolymphatic Hydrops: Utility of iHYDROPS-Mi2 Combined with Deep Learning Reconstruction Denoising

Purpose:

MRI of endolymphatic hydrops (EH) 4 h after intravenous administration of a single dose of gadolinium-based contrast agent is used for clinical examination in some institutions; however, further improvement in image quality would be valuable for wider clinical utility. Denoising using deep learning reconstruction (Advanced Intelligent Clear-IQ Engine [AiCE]) has been reported for CT and MR. The purpose of this study was to compare the contrast-to-noise ratio of endolymph to perilymph (CNR_EP) between the improved hybrid of reversed image of the positive endolymph signal and the native image of the perilymph signal multiplied with the heavily T₂-weighted MR cisternography (iHYDROPS-Mi2) images, which used AiCE for the three source images (i.e. positive endolymph image [PEI], positive perilymph image [PPI], MR cisternography [MRC]) to those that did not use AiCE. We also examined if there was a difference between iHYDROPS-Mi2 images with and without AiCE for degree of visual grading of EH and in endolymphatic area [EL] ratios.

Methods:

Nine patients with suspicion of EH were imaged on a 3T MR scanner. iHYDROPS images were generated by subtraction of PEI images from PPI images. iHYDROPS-Mi2 images were then generated by multiplying MRC with iHYDROPS images. The CNR_EP and EL ratio were measured on the iHYDROPS-Mi2 images. Degree of radiologist visual grading for EH was evaluated.

Results:

Mean CNR_EP ± standard deviation was 1681.8 ± 845.2 without AiCE and 7738.6 ± 5149.2 with AiCE (P = 0.00002). There was no significant difference in EL ratio for images with and without AiCE. Radiologist grading for EH agreed completely between the 2 image types in both the cochlea and vestibule.

Conclusion:

The CNR_EP of iHYDROPS-Mi2 images with AiCE had more than a fourfold increase compared with that without AiCE. Use of AiCE did not adversely affect radiologist grading of EH.

Labyrinthine enhancement on 3D black blood MR images of the brain as an imaging biomarker for cisplatin ototoxicity in (lung) cancer patients

PURPOSE

Cancer patients treated with platinum-based chemotherapy can present with ototoxicity symptoms. The purpose of this work is to report the imaging features related to cisplatin ototoxicity.

METHODS

Between December 2015 and March 2019, a cohort of 96 consecutive patients with lung cancer was selected. Only patients who received cisplatin chemotherapy and underwent an imaging protocol consisting of a Gd-enhanced 3D-BB and 3D-T1W sequence, as well as T2W sequence to exclude metastases, were included. Labyrinthine enhancement was assessed, and all findings regarding the auditory and vestibular function were retrieved from the clinical files.

RESULTS

Twenty-one patients met the inclusion criteria. The Gd-enhanced 3D-BB images were used to divide them into the labyrinth enhancement group (LEG) and the labyrinth non-enhancement group (LNEG). None of these patients demonstrated enhancing regions on the 3D-T1W images. The labyrinthine fluid remained high on the T2 images in all patients, excluding metastases. The LEG consisted of 6 patients. The cochlea and semicircular canals were the most frequently affected regions. All the LEG patients that presented with hearing loss (4/6) had cochlear enhancement. Patients with normal hearing had no cochlear enhancement. Five patients (5/6) showed vestibular enhancement. Four of these patients had vestibular symptoms.

CONCLUSION

Labyrinthine enhancement as an imaging feature related to cisplatin ototoxicity is unreported. This study demonstrates a correlation between hearing loss and cochlear enhancement and also between vestibular impairment and vestibular/semicircular enhancement on 3D-BB images, which remained invisible on the 3D-T1W images. The labyrinthine enhancement on 3D-BB images in the presence of normal signal intensity of the intralabyrinthine fluid can be used as an imaging biomarker for cisplatin toxicity in daily clinical practice and should not be mistaken for intralabyrinthine metastases.

MRI evaluation of the endolymphatic space in otosclerosis and correlation with clinical findings

PURPOSE

The purpose of this study was to investigate the clinical features of ears with otosclerosis and their correlation with endolymphatic hydrops and blood-labyrinth barrier (BLB) impairment on 3T magnetic resonance imaging (MRI).

MATERIALS AND METHODS

This was a single-center retrospective imaging study. Thirty-nine ears from 29 patients (17 men, 12 women; mean age 52±12 [SD] years; range 27-74 years) with non-operated otosclerosis were included. All patients underwent three-dimensional fluid attenuated inversion recovery (FLAIR) MRI sequences performed 4hours after the intravenous administration of a single dose of gadolinium-based contrast material. MRI examinations were analyzed by two radiologists for the presence of saccular hydrops (SH) and BLB impairment. Results of MRI examinations were compared with clinical findings, hearing levels and extent of otosclerotic lesions based on high-resolution computed tomography findings. BLB impairment was evaluated using the signal intensity ratio, ratio of intensities between the basal turn of the cochlea and the medulla.

RESULTS

SH was observed in 1/39 (3%) otosclerotic ears and BLB impairment in 8/39 (21%) while 8/29 patients with otosclerosis (28%) had vertigo. No significant associations were found between SH or BLB impairment on MRI, and the presence of vertigo or the degree of sensorineural hearing loss.

CONCLUSION

Clinical manifestations of otosclerosis (sensorineural hearing loss and rotatory vertigo) were not significantly associated with MRI findings such as BLB impairment and endolymphatic hydrops. SH was only observed in one patient with obstruction of the vestibular aqueduct by an otosclerotic focus.

Comparison of Enhancement of the Vestibular Perilymph between Variable and Constant Flip Angle-Delayed 3D-FLAIR Sequences in Menière Disease

BACKGROUND AND PURPOSE

Endolymphatic hydrops in patients with Menière disease relies on delayed postcontrast 3D-FLAIR sequences. The purpose of this study was to compare the degree of perilymphatic enhancement and the detection rate of endolymphatic hydrops using constant and variable flip angles sequences.

MATERIALS AND METHODS

This was a retrospective study performed in 16 patients with Menière disease who underwent 3T MR imaging 4 hours after gadolinium injection using two 3D-FLAIR sequences with a constant flip angle at 140° for the first and a heavily-T2 variable flip angle for the second. The signal intensity ratio was measured using the ROI method. We graded endolymphatic hydrops and evaluated the cochlear blood-labyrinth barrier impairment.

RESULTS

Both for symptomatic and asymptomatic ears, the median signal intensity ratio was significantly higher with the constant flip angle than with the heavily-T2 variable flip angle (7.16 versus 1.54 and 7.00 versus 1.45, P < .001). Cochlear blood-labyrinth barrier impairment was observed in 4/18 symptomatic ears with the heavily-T2 variable flip angle versus 8/19 with constant flip angle sequences. With heavily-T2 variable flip angle sequences, endolymphatic hydrops was observed in 7-10/19 symptomatic ears versus 12/19 ears with constant flip angle sequences. We found a significant association between the clinical symptomatology and the presence of endolymphatic hydrops with constant flip angle but not with heavily-T2 variable flip angle sequences. Interreader agreement was always perfect with constant flip angle sequences while it was fair-to-moderate with heavily-T2 variable flip angle sequences.

CONCLUSIONS

3D-FLAIR constant flip angle sequences provide a higher signal intensity ratio and are superior to heavily-T2 variable flip angle sequences in reliably evaluating the cochlear blood-labyrinth barrier impairment and the endolymphatic space.

Endolymphatic hydrops evaluation on MRI: Practical considerations

Four-hour delayed three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequence after intravenous gadolinium-based contrast agent administration is an optimal magnetic resonance imaging technique to evaluate endolymphatic hydrops in patients with known or suspected Ménière's disease. Nonenhanced endolymphatic space surrounded by enhanced perilymphatic space is evaluated in the cochlea and vestibule separately. In cochlear hydrops, the scala media is enlarged, potentially obliterating the scala vestibuli. In vestibular hydrops, the size of the saccule becomes equal to or larger than that of the utricle; as hydrops progresses, the saccule and utricle become larger and confluent until complete obliteration of the vestibule's perilymphatic space. In patients with a unilateral clinical presentation of Ménière's disease, it is possible to depict the asymmetries of perilymph enhancement, which may be increased on the affected side and reflect a permeability alteration of the blood-perilymph barrier. In addition, endolymphatic hydrops can be observed in the asymptomatic ear of these patients with a unilateral clinical presentation, showing that Ménière's disease tends to undergo bilateral evolution over time.

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.

Relationship between video head impulse test, ocular and cervical vestibular evoked myogenic potentials, and compartmental magnetic resonance imaging classification in menière's disease

OBJECTIVES/HYPOTHESIS

Currently, it is possible to assess in vivo the morphology of each compartment of the endolymphatic spaces 4 hours after an intravenous administration of gadolinium on magnetic resonance imaging (MRI). The aim of this study was to assess the correlation between otolithic and ampullar functions (cervical vestibular evoked myogenic potential [cVEMP], ocular vestibular evoked myogenic potential [oVEMP], video head impulse test [VHIT]) and delayed inner ear MRI based on a compartmental, anatomically based classification that included the cochlea, the saccule, the utricle, and the ampullas.

STUDY DESIGN

Retrospective case-control study.

METHODS

In this retrospective study, we performed three-dimensional fluid-attenuated inversion recovery sequences with delayed acquisition in 26 healthy subjects and 31 definite Menière's disease (MD) patients. Each subject was then graded on MRI on the basis on cochlear, saccular, utricular, and ampullar hydrops in MD patients. All patients underwent pure-tone audiometry, VHIT, cVEMP, and oVEMP testing.

RESULTS

Cochlear, saccular, utricular, and ampullar hydrops were found on MRI in 88%, 91%, 50%, and 8.5% respectively. We found no significant correlation between the presence of saccular hydrops versus cVEMP, utricular hydrops versus oVEMP, and ampullar hydrops versus VHIT. However, the severity of endolymphatic hydrops on MRI was correlated to the degree of hearing loss.

CONCLUSIONS

We proposed a compartmental, anatomically based classification for endolymphatic hydrops on MRI, which included the whole vestibular compartment. Using this classification, we observed increasing morphological changes as the disease evolved, affecting first the saccule, then the utricle, and finally the ampullas. The severity of vestibular endolymphatic hydrops is only correlated to hearing loss severity.

LEVEL OF EVIDENCE

3 Laryngoscope, 130:E444-E452, 2020.

Biomarkers in Vestibular Schwannoma-Associated Hearing Loss

Vestibular schwannomas (VSs) are benign tumors composed of differentiated neoplastic Schwann cells. They can be classified into two groups: sporadic VS and those associated with neurofibromatosis type 2 (NF2). VSs usually grow slowly, initially causing unilateral sensorineural hearing loss (HL) and tinnitus. These tumors cause HL both due to compression of the auditory nerve or the labyrinthine artery and due to the secretion of different substances potentially toxic to the inner ear or the cochlear nerve. As more and more patients are diagnosed and need to be managed, we are more than ever in need of searching for biomarkers associated with these tumors. Owing to an unknown toxic substance generated by the tumor, HL in VS may be linked to a high protein amount of perilymph. Previous studies have identified perilymph proteins correlated with tumor-associated HL, including μ-Crystallin (CRYM), low density lipoprotein receptor-related protein 2 (LRP2), immunoglobulin (Ig) γ-4 chain C region, Ig κ-chain C region, complement C3, and immunoglobulin heavy constant γ 3. Besides, the presence of specific subtypes of heat shock protein 70 has been suggested to be associated with preservation of residual hearing. It has been recently demonstrated that chemokine receptor-4 (CXCR4) is overexpressed in sporadic VS as well as in NF2 tumors and that hearing disability and CXCR4 expression may be correlated. Further, the genetic profile of VS and its relationship with poor hearing has also been studied, including DNA methylation, deregulated genes, growth factors, and NF2 gene mutations. The knowledge of biomarkers associated with VS would be of significant value to maximize outcomes of hearing preservation in these patients.