MRI imaging of Meniere's disease/syndrome

"Bleeding edge" medical technology as of 2019.

Timothy C. Hain, MD • Page last modified: March 5, 2021

 

Hydrops means that the pressure in endolymphatic compartment of the inner ear is elevated. Dogma states that all persons with Meniere's disease have hydrops.

Recently MRI resolution has become good enough that it is possible to image the inner ear and diagnose hydrops from normal using imaging. Dye must be used in this situation. Dye can be administered intravenously, or placed within the middle ear so it can diffuse through the round window. The latter method is rarely used, but may increase as recent work suggests that gadolinium is not ototoxic (in mice), (Nonoyama et al, 2016). 3D-Flair imaging is used to minimize undesired ghosts of CSF flow (Yamazaki et al, 2012)

At this writing (2018), it is clear that 3T MRI can be used to identify hydrops, and might be useful in diagnosing Meniere's disease. Practically however, most radiology facilities are unable to do this test, and right now it is a "bleeding edge" area of medicine. As we discuss elsewhere, it is very unusual for MRI to discover a tumor in a person with "classic" Meniere's, so this isn't a good reason to do MRI either.

The current "standard" method appears to include imaging at 4 hours after IV injection in a 3T scanner, using highly T2 weighted Flair. Flair is fluid attenuated inversion recovery. Contrast accumulates in the perilymph which appears bright on Flair. The endolymphatic compartment appears dark.

Several groups suggest using double-dose gadolinium. The method of injection of gadolinium through the TM or through the eustachian tube, though more sensitive, is less frequently used. When it is used, the imaging is done 24 hours later.

This method appears to be very successful in documenting hydrops in Meniere's patients (Ito et al, 2016). This method is "emerging", and not offered by most radiology departments.

Dr. A Sephardi (2015), was kind enough to provide the images below that are examples of the MRI in patients with Meniere's. They used a subtraction technique now that shows the perilymph signal as white, the endolymph as black, and the surrounding bone as a medium gray. It makes it easier to distinguish the membranous labyrinth from the otic capsule in some areas. The text below and images are from Dr. Sephardi:

In normal patients, the utricle is well seen and occupies about 50% of the vestibule at the level of the lateral semicircular canal, whereas the saccule and cochlear duct are imperceptibly small. These areas appear virtually entirely filled with perilymph (white). With hydrops, the saccule fills the anterior/inferior vestibule, and the cochlear duct dilates to efface the scala vestibuli. The net effect is an appearance of alternating white and black bands in the cochlea. Utricle hydrops is less common, and usually only seen if there is also saccule and cochlear duct hydrops.

Dr. Sephardi stated -- "We also routinely assess for asymmetry in post-contrast perilymph signal intensity. We often see higher perilymph signal intensity on the symptomatic side in unilateral MD. We believe this is due to increased blood-labyrinth barrier permeability. This increased post-contrast effect (enhancement of pathologic side) was originally published by Yamazaki et al, 2012.

Review of literature 2012-2019:

• Shi et al (2019) reported on partial endolymphatic hydrops in patients who underwent 4 hour delayed IV gadoliunium imaging. They reported "Of the 338 collected patients with definite MD, 19 patients (5.6%) had unilateral vestibular ELH (N = 18) or cochlear ELH (N = 1), and 4 patients (1.2%) with bilateral ELH had contralateral cochlear ELH". This data is a little hard to interpret given that it depends on a correlation of clinical criteria with imaging. One would wonder what imaging might reveal in a similar number of patients with no inner ear symptoms (i.e. either hearing or vertigo).
• Shi et al (2018). This study reported 96.1% of 154 patients with "definite" Meniere's had hydrops. They used 4 hour delayed imaging They also noted an "elevated contrast effect" on the affected side.
• Keller et al (2017) reported that hydrops can be detected from standard MRI imaging. [We find this puzzling as in our institution, we don't find the images done with higher resolution methods useful, and we doubt that a lesser technique would be sufficient].
• Wu et al (2016) reported that hydrops on MRI correlates with hearing. Bilateral intratympanic injection was used. [We think it would be a little risky to use IT injection].
• Sephardi et al (2016) reported reversal of hydrops following diuretic treatment. This is an important advance considering the literature that suggests that diuretic treatment is ineffective in Meniere's disease.
• Ito et al (2016) reported that " Cochlear EH was present in 3.3% of 30 ears of 15 controls, 6.3% of 32 contralateral (contra) ears of 32 uMDs, 62.5% of 32 affected ears of 32 uMDs, and 55.6% of 18 affected ears of nine bMDs. Vestibular EH was observed in 6.7% of control ears, 3.1% of contra-uMD ears, 65.6% of affected uMD ears, and in 55.6% of affected bMD ears. Either cochlear or vestibular EH was present in 10.0% of control ears, 6.3% of contra-uMD ears, 81.3% of affected uMD ears, and 44.4% of affected bMD ears." This shows roughly a 10 times greater finding of hydrops in MD patients. This study does not mention blinding.
• Sepahdari et al (2015) reported that using 3D-Flair MRI, 3D MIP projections were superior to 2D Images.
• Liu et al (2015) reported that 3D flair performed on a 3T unit 24 hours after IT injection of gadolinium. Comment: IT injection is not the usual method. We think this could be a little risky.
• Another Liu (2014) reported in normal subjects, again using 3D Flair and a 3T unit, that 24 hours after installation of gadolinium via the ET, that the normal value of the endolymphatic space in the cochlea ranges between 7-27%, and in the vestibule, 17-39%. No changes in hearing or tympanometry were noted from the installation of gadolinium.
• Hormann et al(2015) reported again using 3T MRI with highly weighted FLAIR and T2DRIVE sequencies. They reported that endolymphatic space was larger in patients with prolonged Meniere's.
• Nonoyama et al (2014) reported 3D Flair scanning results in patients using 0.2 mg/kg of GBCA. The MRI was performed 4 hours after IV GBCA.
• Mukaida, T., et al. (2014). "Magnetic Resonance Imaging Evaluation of Endolymphatic Hydrops in Cases with Otosclerosis." Otol Neurotol.
• Liu Y (2014) reported that sac surgery reduced endolymphatic volume. This was done with 24 hour delayed scans from administration through the eustachian tube.
• Homann (2014) reported use of HT2w-Flair 4 hours after IV contrast.
• Hagiwara, M., et al. (2014). Suggested that 3D color map was superior to gray scale MRI.
• Gu et al (2014) suggested that a formal scoring system provided diagnostic accuracy. This makes some sense.
• Barath (2014) reported that 3D inversion recovery sequence 4 hours post IV contrast was identified with high reliability in 53 patients.
• Uno et al (2013) reported that sac surgery reduced hydrops as measured by FLAIR 4 hours or 24 hours post IV contrast.
• Uno et al (2013) reported that either intratympanic or IV Gd administration was equivalent. The criteria were as follows: The endolymphatic space was detected as a low signal intensity area, while the surrounding perilymphatic space showed high intensity with Gd contrast. Those cases in which low signal areas corresponding to the cochlear duct could be clearly noticed, were classified as cochlear hydrops. When the greater part of the vestibule was occupied by a low signal area in more than half of the images, it was classified as vestibular hydrops.
• Shimono et al (2013) evaluated 3T MRI 4 hours after IV injection or 24 hours after intratympanic injection, in patients with acute low-tone SNHL.
• Seo et al (2013) commented that "cochlea hydrops and vestibular (saccular) hydrops are readily visualized using these techniques. Hydrops, as visualized on MRI, may be a reliable means to diagnosis Meniere's disease; this is supported by appropriate correlations with auditory vestibular functional testing" They used 3T contrast MRI.
• Kato et al (2013) suggested that hydrops that predominates in the vestibule have more vestibular symptoms than hydrops in the cochlea.
• Lida et al (2013) reported that intratympanic and IV contrast localize differently in the ear, with a more uniform distribution in the IV group.
• Gurkov et al (2013) reported that betahistine medication had no effect on hydrops measured by MRI. Comment: This would fit best with the idea that betahistine does not affect hydrops.
• Sano et al (2012) found that 4 hour delay is more effective than 10 minute delayed imaging. They used 0.1/kg dose. This is a low dose.
• Grieve et al (2012) stated that it is possible to image hydrops using a 1.5 T scanner. They used 24 hour imaging after IT injection.

How to order an MRI for hydrops.

Rx: 3T MRI of the inner ear, 3D Flair, 4 hours after double dose IV gadolinium.

It is not enough to simply order this test. One must also establish a "protocol" with your radiologists, who also need to do more work to interpret them. We think that ideally one's radiologists should provide the ratio of endolymph volume to perilymph volume, for both the cochlea and vestibule. More about this is found below.

The FLAIR variant is sometimes constant or has a variable flip angle.

Investigators	Gad dose	Thick (mm)	TR (ms)	TE (ms)	TI (ms)	Flip angle	Matrix	Bandwidth	Turbo	Misc
Barath et al (2014)	0.2 mmol/kg (double)	0.8	6000	177	2000	180	384	213	27
Yamazaki et al (2012)	0.2 mmol (double)	0.8	9000	458	2500	120	256
Ito et al (2016)	0.2 ml/kg (standard)				2250					Subtracted PEI from PPI
Sephardi et al(2015)	0.2 mmol/kg (double)	0.8	9000	534	2350	120	320x260			Fov 200x167

There are many options how to go about this as can be seen from the table above.

The imaging plane is axial, not coronal or sagittal.

Most recent authors use "double dose constrast", which is 0.2 mmol/kg. This can be a bit confusing as the ml/kg standard dose is 0.2 ml/kg, which can be mixed up with the 0.2 mmol/kg. A 0.4 mL/Kg body weight dose, is the same as 0.2 mmol/kg body weight. (Yamazaki et al, 2012; Nakashima et al, 2010).

There are innumerable variants of FLAIR with nearly every paper opting for a different combination of parameters. Sephardi et al (2015) noted that the hT2w-3D flair images were preferable to the standard T2 Flair.

Although often not mentioned, one also needs an MRI sequence that shows both perilymph and endolymph to help determine the area of the entire labyrinth.

Ito et al (2016) used "heavily T2 weighted MRI cisternography -- (hT2W MRC) for this purpose.

Barah et al (2014) used a "SPACE" T2 weighted sequence. Sephardi et al (2015) did the same using a SPACE cisternographic 3D turbo spin echo T2 (on a Siemans Skyra scanner).

Another group, Bykowski et al (2015) used Fiesta as a comparison. Fiesta is the GE name for a steady-state gradient echo sequence. The naming of these protocols varies depending on the manufacturer of the MRI device.

How to read an MRI for hydrops

Thus what one is looking for is the percent of endolymph of the total fluid space in both the cochlea and vestibule.

In normal subjects, Liu et al (2012) found endolymph (black area) in 20 normal subjects to account for 8-26% of the fluid space within the cochlea, and 20-41% of the vestibule. This study was done using dye inserted through the eustachian tube and 24 delayed imaging -- so somewhat of an apples/oranges compared to the current evolving standard. One would think there would be more dye and better definition than subsequent studies using IV contrast.

The trouble with current methodology is that the imaging is imperfect (fuzzy), and guesswork is needed to estimate these numbers.

The general method of is to make high resolution axial Flair images of the inner ear, digitally magnify them, find known structures (i.e. cochlear, vestibule, semicircular canals), and determine how much of them (i.e. area) is white (perilymph) vs black (endolymph). More black means more hydrops. Bigger "strips" in the cochlea, and a larger black area in the vestibule, and loss of the expected loops of the semicircular canals means more hydrops. There are some practical issues as these protocols may take 15 minutes (Bykowski et al, 2015) -- about 5 minutes for the FLAIR and another 5 minutes for a comparison non-flair sequence. In addition, it takes the radiologists more time to read these as they have to compute areas.

Barath et al (2014) used three sets of axial sections -- "below midmodiolar level", "midmodiolar level", and "above midmodiolar level". In other words, through the center, and (presumably) one section above and below. An example of these is shown below. The utricle is higher and the saccule is lower, and the utricle is more horizontally oriented than the saccule.

As endolymph is black on this type of imaging, one might wonder - - how can one see the endolymph vs. other black structures such as surrounding bone ? Although Barath (2014) is not explicit, from their figure 2, it appears they used a highly T2 weighted sequence (called "SPACE"), at 0.4 mm resolution with the objective of seeing fluid whether or not it has contrast. This should show both endolymph and perilymph at the same time. Thus it appears that they use two different image resolutions, and compared the Flair to T2 when there were difficulties in deciding what was endolymph and perilymph.

Sephardi et al (2015) reported regarding their method that "an axial image through the vestibule at the level of the LSC was identified. A freehand region of interest was drawn around the VES and ROI area was recorded. A second freehand ROI was drawn around the entire vestibule which included both the vestibualr perilymph (bright signal) and the vestibular endolymph (dark signal). The VES/vestibule ratio was then calculated. Thus Sephardi et al quantified vestibular hydrops, but did not measure cochlear hydrops. These authors also noted that endolymph was sometimes difficult to distinguish from bone at some levels, and they recommended computing hydrops at the level of the LSC.

Rating scales:

A common feature to rating scales is that they differ between the cochlea and the vestibule. This is because of the difference in volume of the endolymphatic compartment in these two structures in normal subjects.

 

Nagoya hospital criteria from Nakashima et al, 2009.	Scoring of Vestibule from Nakashima et al, 2009. On the right, the area of the darker and enhanced (perilymph) portions of the vestibule are outlined. The paper states that the area ratio here between the inner and outer is 67.5%.

 

Nakashima et al (2009) used the "2008 Nagoya scale". They compared the ratio of the endolymphatic space to the sum of the endolymphatic and perilymphatic space. Note that the images above were made with contrast in the middle ear rather than with intravenous contrast -- i.e. it is presumably higher concentration.

For the vestibular labyrinth, no hydrops was defined as < 1/3. Mild hydrops between 1/3-1/2, and "significant hydrops", greater than 50%.

For the cochlea, mild hydrops was defined as the area of the endolymphatic space not greater than the area of the scala vestibuli, and in "significant hydrops", the endolymphatic space in the cochlea area exceeded the area of the scala vestibuli. As illustrated above, there is clearly some opportunity for subjective judgement here deciding on the borders of the perilymphatic space, as well as deciding how to separate perilymph as part of the vestibule from perilymph in other structures of the inner ear.

Example of scoring from Barath et al, 2014. On the left is Flair sequence where endolymph is black and perilymph is white, on right is T2 sequence where fluid, endolymph or perilymph, is all white.

Barath et al (2014) also suggested 6 different ratings: Grades 0-2 (normal, mild and severe), and cochear or vestibular.

Barath et al (2014) stated that more than 50% (black) within the total volume of the saccule and utricle was required for their hydrops grade 1 (mild). Grade 2 (severe) was 100% black. Compared to the Nagoya criteria, the Barath "mild" is equivalent to the Nagoya "significant" -- thus the Barath system is more conservative as it requires more hydrops to be scored as abnormal, for the vestibule.

Barath et al did not provide quantitative criteria for rating cochlear hydrops, but presumably it would take more prominent "stripes" of the cochlea to be rated as either mild or severe. As Barath et al did not provide numerical criteria, here one would presumably need to use the Nagoya criteria.

References:

• Barath, K., et al. (2014). "Detection and grading of endolymphatic hydrops in Meniere disease using MR imaging." AJNR Am J Neuroradiol 35(7): 1387-1392.
• Bykowski, J., et al. (2015). "Intratympanic Contrast in the Evaluation of Meniere Disease: Understanding the Limits." AJNR Am J Neuroradiol 36(7): 1326-1332.
• Grieve, S. M., et al. (2012). "Imaging of endolymphatic hydrops in Meniere's disease at 1.5 T using phase-sensitive inversion recovery: (1) demonstration of feasibility and (2) overcoming the limitations of variable gadolinium absorption." Eur J Radiol 81(2): 331-338.
• Gurkov, R., et al. (2013). "Effect of standard-dose Betahistine on endolymphatic hydrops: an MRI pilot study." Eur Arch Otorhinolaryngol 270(4): 1231-1235.
• Gu, X., et al. (2014). "Diagnostic value of three-dimensional magnetic resonance imaging of inner ear after intratympanic gadolinium injection, and clinical application of magnetic resonance imaging scoring system in patients with delayed endolymphatic hydrops." J Laryngol Otol 128(1): 53-59.
• Hagiwara, M., et al. (2014). "Identification of endolymphatic hydrops in Meniere's disease utilizing delayed postcontrast 3D FLAIR and fused 3D FLAIR and CISS color maps." Otol Neurotol 35(10): e337-342.
• Homann, G., et al. (2014). "HR 3 Tesla MRI for the diagnosis of endolymphatic hydrops and differential diagnosis of inner ear tumors--demonstrated by two cases with similar symptoms." Rofo 186(3): 225-229.
• Homann, G., et al. (2015). "Semi-quantitative vs. volumetric determination of endolymphatic space in Meniere's disease using endolymphatic hydrops 3T-HR-MRI after intravenous gadolinium injection." PLoS One 10(3): e0120357.
• Ito T, Kitahara T, Inui H, Miyasaka T, Kichikawa K, Ota I, Nario K, Matsumura Y, Yamanaka T.Endolymphatic space size in patients with Meniere's disease and healthy controls. Acta Otolaryngol. 2016 Apr 15:1-4. [Epub ahead of print]
• Kato, M., et al. (2013). "Endolymphatic hydrops revealed by magnetic resonance imaging in patients with atypical Meniere's disease." Acta Otolaryngol 133(2): 123-129.
• Keller JH, Hirsch BE, Marovich RS, Branstetter BF 4th. .Detection of endolymphatic hydrops using traditional MR imaging sequences. Am J Otolaryngol. 2017 Apr 6. pii: S0196-0709(16)30622-6. doi: 10.1016/j.amjoto.2017.01.038. [Epub ahead of print]
• Iida, T., et al. (2013). "Magnetic resonance imaging of the inner ear after both intratympanic and intravenous gadolinium injections." Acta Otolaryngol 133(5): 434-438.
• Liu, F., et al. (2012). "Comparison of noninvasive evaluation of endolymphatic hydrops in Meniere's disease and endolymphatic space in healthy volunteers using magnetic resonance imaging." Acta Otolaryngol 132(3): 234-240.
• Liu, F., et al. (2014). "Noninvasive evaluation of the effect of endolymphatic sac decompression in Meniere's disease using magnetic resonance imaging." Acta Otolaryngol 134(7): 666-671.
• Liu, F., et al. (2015). "Comparison of noninvasive evaluation of endolymphatic space in healthy volunteers in different age groups using magnetic resonance imaging." Acta Otolaryngol 135(5): 416-421.
• Liu, Y., et al. (2015). "Endolymphatic hydrops detected by 3-dimensional fluid-attenuated inversion recovery MRI following intratympanic injection of gadolinium in the asymptomatic contralateral ears of patients with unilateral Meniere's disease." Med Sci Monit 21: 701-707.
• Mukaida et al (2014) used 3T MRI 4 hours after IV injection of gadolinium in otosclerosis patients, and found hydrops in some.
• Nakashima, T., et al. (2009). "Grading of endolymphatic hydrops using magnetic resonance imaging." Acta Otolaryngol Suppl 129: 5-8.
• Nakashima, T., et al. (2010). "Endolymphatic hydrops revealed by intravenous gadolinium injection in patients with Meniere's disease." Acta Otolaryngol 130(3): 338-343.
• Nonoyama, H., et al. (2014). "Evidence for bilateral endolymphatic hydrops in ipsilateral delayed endolymphatic hydrops: preliminary results from examination of five cases." Acta Otolaryngol 134(3): 221-226.
• Nonoyama, H., et al. (2016). "Investigation of the ototoxicity of gadoteridol (ProHance) and gadodiamide (Omniscan) in mice." Acta Otolaryngol: 1-6.
• Sano, R., et al. (2012). "Contrast enhancement of the inner ear in magnetic resonance images taken at 10 minutes or 4 hours after intravenous gadolinium injection." Acta Otolaryngol 132(3): 241-246.
• Seo, Y. J., et al. (2013). "Visualization of endolymphatic hydrops and correlation with audio-vestibular functional testing in patients with definite Meniere's disease." Auris Nasus Larynx 40(2): 167-172.
• Sepahdari, A. R., et al. (2015). "Delayed intravenous contrast-enhanced 3D FLAIR MRI in Meniere's disease: correlation of quantitative measures of endolymphatic hydrops with hearing." Clin Imaging 39(1): 26-31.
• Sepahdari, A. R., et al. (2016). "Endolymphatic Hydrops Reversal following Acetazolamide Therapy: Demonstration with Delayed Intravenous Contrast-Enhanced 3D-FLAIR MRI." AJNR Am J Neuroradiol 37(1): 151-154.
• Shi S, Guo P, Wang W. Magnetic Resonance Imaging of Ménière's Disease After Intravenous Administration of Gadolinium. Ann Otol Rhinol Laryngol. 2018 Aug 29:3489418794699. doi: 10.1177/0003489418794699
• Shi S, Zhou F, Wang W.3D-real IR MRI of Meniere's disease with partial endolymphatic hydrops. Am J Otolaryngol. 2019 May 15. pii: S0196-0709(19)30258-3. doi: 10.1016/j.amjoto.2019.05.015. [Epub ahead of print]
• Shimono, M., et al. (2013). "Endolymphatic hydrops revealed by magnetic resonance imaging in patients with acute low-tone sensorineural hearing loss." Otol Neurotol 34(7): 1241-1246.
• Uno, A., et al. (2013). "Changes in endolymphatic hydrops after sac surgery examined by Gd-enhanced MRI." Acta Otolaryngol 133(9): 924-929.
• Uno, A., et al. (2013). "[Endolymphatic hydrops detected with inner ear gd contrast-enhanced MRI; comparison between administration routes or with ECochG or glycerol test]." Nihon Jibiinkoka Gakkai Kaiho 116(8): 960-968.
• Yamazaki, M., et al. (2012). "Comparison of contrast effect on the cochlear perilymph after intratympanic and intravenous gadolinium injection." AJNR Am J Neuroradiol 33(4): 773-778.
• Wu, Q., et al. (2016). "The correlation between symptoms of definite Meniere's disease and endolymphatic hydrops visualized by magnetic resonance imaging." Laryngoscope 126(4): 974-979.

Written By: Timothy C. Hain, MD of Chicago Dizziness and Hearing.