BRAIN
MRA BRAINMRV BRAINPEDIATRIC BRAINORBITIAMSDWI IAMSPNSSELLAEPILAPSYTMJ'STRIGEMINALFACENECK sialographyC SPINEMRA NECKB PLEXUSMRA SUB CLAVIANSCHESTSTRENUMT SPINECARDIACKIDNEYSMRA RENALADRENALLIVERMRCPPANCREASSECRITEN MRCPSMALL BOWELmrv abdomenBREASTIMPLANT BREASTRECTAL CA BLADDERURETHRAPROSTATEPENIS TESTISGYNE PELVISPLACENTAVEGINAL FISTULAFISTULAProctogramHIPSARTHROGRAM HIPPSOSL SPINESI JOINTSL PLEXUSKUBMR UROGRAPHYTHIGHKNEETIB AND FIBANKLEFOOTMRA LEGSSHOULDERARTHROGRAM SHOULDERHUMORUSELBOWFOREARMWRISTHANDMRA ARMMRA HANDMRA WHOLE BODYmiscellaneous

 

 

 

 

 

 

 

 

Indications for internal auditory meatus(iams) MRI scan

> Sensorineural hearing loss (SNHL)
> Acoustic neuroma
> Ringing in the ears
> Dizziness
> Fullness
> Tumour
> Trauma
> Tinnitus
> Vertigo.

Contraindications internal auditory meatus(iams) MRI scan





Any electrically, magnetically or mechanically activated implant (e.g. cardiac pacemaker, insulin pump biostimulator, neurostimulator, cochlear implant, and hearing aids)
Intracranial aneurysm clips (unless made of titanium)
Pregnancy (risk vs benefit ratio to be assessed)
Ferromagnetic surgical clips or staples
Metallic foreign body in the eye
Metal shrapnel or bullet

Patient preparation internal auditory meatus(iams) MRI scan







>

A satisfactory written consent form must be taken from the patient before entering the scanner room
Ask the patient to remove all metal objects including keys, coins, wallet, cards with magnetic strips, jewellery, hearing aid and hairpins
If possible provide a chaperone for claustrophobic patients (e.g. relative or staff )

Contrast injection risk and benefits must be explained to the patient before the scan
Gadolinium should only be given to the patient if GFR is > 30

Offer earplugs or headphones, possibly with music for extra comfort
Explain the procedure to the patient
Instruct the patient to keep still
Note the weight of the patient

Positioning




Head first supine
Position the head in the head coil and immobilise with cushions
Give cushions under the legs for extra comfort
Centre the laser beam localizer over the glabella

Suggested protocols, parameters and planning

localiser

A three plane localiser must be taken in the beginning to localise and plan the sequences. Localizers are normally less than 25sec. T1 weighted low resolution scans.

T2 tse axial

Plan the axial slices on the sagittal plane; angle the position block parallel to the anterior and posterior margin of the corpus callosum. Slices must be sufficient to cover the whole brain from the vertex up to the line of the foramen magnum. Check the positioning block in the other two planes. An appropriate angle must be given in coronal plane on a tilted head (perpendicular to the line of 3rd ventricle and brain stem).

Parameters

TR

3000-4000

TE

100-120

SLICE

5MM

FLIP

130-150

PHASE

R>L

MATRIX

320X320

FOV

210-230

GAP

10%

NXA(AVRAGE)

2

T2 TSE coronal

Plan the coronal slices on the axial plane; angle the position block parallel to the line along right and left IAMS(as shown in the diagram).Check the positioning block in the other two planes. An appropriate angle must be given in the sagittal plane (parallel to the brain stem). Slices must be sufficient to cover IAMS from the posterior border of sphenoid sinus up to the line of the fourth ventricle.

internal auditory meatus(IAM'S) MRI protocols and planning of coronal t2 scans

Parameters

TR

3000-4000

TE

110

FLIP

130

NXA

2

SLICE

3MM

MATRIX

256X256

FOV

150-180

PHASE

R>L

GAP

10%

SLICE

10-20%

3D CISS,(3D SPACE or 3DFIESTA) axial

Plan the axial slices on the coronal plane; angle the position block parallel to the line along right and left IAMS(as shown in the diagram).Check the positioning block in the other two planes. An appropriate angle must be given in the sagittal plane (perpendicular to the brain stem). Slices must be sufficient to cover IAMS from the hippocampus up to the line of the C1 verbal body.

internal auditory meatus(IAM'S) MRI protocols and planning of axial ciss /space scans

Parameters CISS

TR

12-15

TE

6-7

SLICE

.8mm

FLIP

80

PHASE

R>L

MATRIX

384X320

FOV

210-230

GAP

10%

NXA(AVRAGE)

1

 

T1 pre contrast and post contrast scans are only required in case of tumor present in internal auditory canal.

 

T1 TSE coronal

Plan the coronal slices on the axial plane; angle the position block parallel to the line along right and left IAMS(as shown in the diagram).Check the positioning block in the other two planes. An appropriate angle must be given in the sagittal plane (parallel to the brain stem). Slices must be sufficient to cover IAMS from the posterior border of sphenoid sinus up to the line of the fourth ventricle.

internal auditory meatus(IAM'S) MRI protocols and planning of axial t1 scans

Parameters

TR

400-500

TE

15

FLIP

150

NXA

3

SLICE

3MM

MATRIX

256X256

FOV

150-180

PHASE

R>L

GAP

10%

SLICE

10-20%

T1 TSE axial

Plan the axial slices on the coronal plane; angle the position block parallel to the line along right and left IAMS(as shown in the diagram).Check the positioning block in the other two planes. An appropriate angle must be given in the sagittal plane (perpendicular to the brain stem). Slices must be sufficient to cover IAMS from the hippocampus up to the line of the C1 verbal body.

Parameters

TR

400-600

TE

150

SLICE

3mm

FLIP

90

PHASE

R>L

MATRIX

256X256

FOV

170-180

GAP

10%

NXA(AVRAGE)

3

 

Use T1 SE axial and coronal after the administration of IV gadolinium DTPA injection(copy the planning outlined above). The recommended dose of gadolinium DTPA injection is 0.1 mmol/kg, i.e. 0.2 mL/kg in adults, children and infants.

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