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IAM'S (Ménière’s disease protocol)

Ménière’s disease

Ménière’s disease, also known as endolymphatic hydrops, is a disorder of the inner ear that affects both hearing and balance. It is named after the French physician Prosper Ménière, who first described the condition in the 1860s.

The main symptoms of Ménière’s disease include:

  • Vertigo: A sensation of spinning or dizziness that can be severe and disabling.

  • Tinnitus: Ringing, buzzing, or other noises in the ear.

  • Hearing loss: Episodes of hearing loss, which may fluctuate and eventually become permanent in some cases.

  • A feeling of fullness or pressure in the affected ear.

The exact cause of Ménière’s disease is not fully understood, but it is believed to be related to a build-up of fluid in the inner ear, known as endolymphatic hydrops. This fluid imbalance disrupts the normal functioning of the inner ear structures responsible for hearing and balance.

Ménière’s disease can occur at any age, but it is most common in individuals between the ages of 40 and 60. The condition can be unpredictable, with sudden attacks of vertigo and other symptoms that may last for hours to days. Over time, it can lead to permanent hearing loss and ongoing balance issues.

Treatment for Ménière’s disease aims to manage symptoms and includes dietary changes, medication to control vertigo and nausea, and sometimes surgical interventions in severe cases.

The latest advancements in MRI  have enabled radiologists to identify cochlear or vestibular EH by utilizing post-contrast FLAIR 3D imaging. This particular imaging is conducted after the administration of IV gadolinium, approximately 4 hours later. For optimal results, it is recommended to conduct these scans using a 3T scanner.

Indications for the scan

Contraindications of MRI scan

Patient preparation internal auditory meatus(iams) MRI scan

Positioning

MRI Internal Auditory Meatus(IAM'S) scan positioning

MRI Ménière’s disease Protocols, Parameters, and Planning

localiser

A three-plane localizer must be taken at the beginning to localize and plan the sequences. Localizers are usually less than 25 seconds and are T1-weighted low-resolution scans.

T2 tse axial 5mm

Plan the axial slices on the sagittal plane and position the block parallel to the genu and splenium of the corpus callosum. Verify the planning block in the other two planes and ensure that an appropriate angle is maintained in the coronal plane, making it perpendicular to the line of the midline of the brain and the 4th ventricle. Ensure that the number of slices is sufficient to cover the entire brain from the vertex to the line of the foramen magnum.

mri brain protocol and planning of axial scans

Parameters

TR

3000-4000

TE

100-120

SLICE

5MM

FLIP

130-150

PHASE

R>L

MATRIX

320X320

FOV

210-230

GAP

10%

NEX(AVRAGE)

2

T2 TSE coronal 3mm

Plan the coronal slices on the axial plane and angle the planning block parallel to the line along the right and left Internal Auditory Meatus (IAMS) (as shown in the diagram). Verify the planning block in the other two planes. Ensure an appropriate angle is maintained in the sagittal plane, parallel to the brain stem. The number of slices should be sufficient to cover the IAMS from the posterior border of the sphenoid sinus up to the line of the fourth ventricle.These coronal T2 scans are performed to aid in the planning of axial 3D scans.

mri planing and protocol of Internal Auditory Meatus (IAMS) coronal planning

Parameters

TR

3000-4000

TE

110

FLIP

130

NEX

2

SLICE

3MM

MATRIX

256X256

FOV

150-180

PHASE

R>L

GAP

10%

SLICE

10-20%

T2 3D SPACE (3D CISSor 3DFIESTA) axial .5mm

Plan the axial slices on the coronal plane and angle the planning block parallel to the line along the right and left internal auditory meatus (IAMS), as shown in the diagram. Verify the planning block in the other two planes. Ensure an appropriate angle is maintained in the sagittal plane, perpendicular to the brain stem. The number of slices should be sufficient to cover the IAMS from the hippocampus up to the line of the C1 vertebral body.

mri planing of iam axial cissor SPACE 3D

Parameters CISS

TR

12-15

TE

6-7

SLICE

.8mm

FLIP

80

PHASE

R>L

MATRIX

384X320

FOV

210-230

GAP

10%

NEX(AVRAGE)

1

For contrast enhanced delayed scans

The most crucial sequence for detecting Ménière's disease is a post-contrast 4-hour delayed 3D Flair sequence. This particular imaging technique is highly valuable as it allows the radiologist to effectively identify cochlear or vestibular EH (hydrops). To optimize results, it is recommended to increase the gadolinium dosage while performing the scans. For the most ideal outcomes, utilizing a 3T scanner is highly recommended. The document below grants access to the manufacturer's recommended dosage of gadolinium DTPA injection.

T2 SPACE FLAIR 3D axial .8mm Delayed 4 hours

Plan the axial slices on the coronal plane and angle the planning block parallel to the line along the right and left internal auditory meatus (IAMS), as shown in the diagram. Verify the planning block in the other two planes. Ensure an appropriate angle is maintained in the sagittal plane, perpendicular to the brain stem. The number of slices should be sufficient to cover the IAMS from the hippocampus up to the line of the C1 vertebral body.

mri planning of iam Ménière's disease 3D FLAIR delayed 4 hours imaging

T2 SPACE FLAIR 3D axial .8mm images

Ménière’s disease axial flair 3D images

T2 SPACE FLAIR 3D coronal reconstructed images

Ménière’s disease coronal flair 3D reconstructed images

Parameters

TR

6000-7000

TE

300-400

SLICE

.7mm

TI

2050

PHASE

R>L

MATRIX

224X224

FOV

200-230

GAP

10%

NXA(AVRAGE)

2