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MRI Orbits : Protocol and Planning

Indications for MRI Orbits scan

Contraindications

Patient preparation for MRI Orbits scan

Positioning for MRI Orbits scan

MRI orbits positioning

Recommended MRI Orbits Protocols, Parameters, and Planning

localiser 1

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

Orbits MRI localiser image

localiser 2

Plan a second T2 three-plane localizer on the first localizer. Plan the sagittal localizer on the axial image and make it parallel to the optic nerve. Plan the coronal localizer perpendicular to the right and left optic nerve, as shown in the image. Finally, plan the axial localizer in the coronal image and make it parallel to the right and left optic nerve.

Orbit MRI localiser planning image

T2 tse axial

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 stir coronal 3mm

Plan the coronal slices on the axial plane and angle the planning block parallel to the right (RT) and left (LT) optic nerve. Check the planning block in the other two planes. An appropriate angle must be given in the sagittal plane (perpendicular to the optic nerve). Ensure that the slices are sufficient to cover the entire orbits from the eye lenses to the optic chiasm.”

MRI ORBITS PLANNING OF CORONAL SCANS

Parameters

TR

4000-5000

TE

110

FLIP

160

NEX

3

SLICE

3MM

MATRIX

256×256

FOV

150-170

PHASE

R>L

GAP

10%

TI

150

T1 TSE coronal 3mm

Plan the coronal slices on the axial plane and angle the planning block parallel to the right (RT) and left (LT) optic nerve. Check the planning block in the other two planes. An appropriate angle must be given in the sagittal plane (perpendicular to the optic nerve). Ensure that the slices are sufficient to cover the entire orbits from the eye lenses to the optic chiasm.”

MRI ORBITS PLANNING OF CORONAL SCANS

Parameters

TR

400-600

TE

15-25

SLICE

3MM

FLIP

150

PHASE

R>L

MATRIX

256X256

FOV

150×170

GAP

10%

NEX(AVRAGE)

3

T2 stir axial

Plan the axial slices on the coronal plane and angle the planning block parallel to the right (RT) and left (LT) optic nerve. Check the planning block in the other two planes. Provide an appropriate angle in the sagittal plane (parallel to the optic nerve). Ensure that the slices are sufficient to cover the entire orbits from the superior border to the inferior border.

MRI ORBITS PLANNING OF AXIAL SCANS

Parameters

TR

4000-5000

TE

110

FLIP

160

NEX

3

SLICE

3MM

MATRIX

256×256

FOV

150-170

PHASE

R>L

GAP

10%

TI

150

RESOLVE DWI 2trace axial

Plan the axial slices on the coronal plane and angle the planning block parallel to the right (RT) and left (LT) optic nerve. Check the planning block in the other two planes. Provide an appropriate angle in the sagittal plane (parallel to the optic nerve). Ensure that the slices are sufficient to cover the entire orbits from the superior border to the inferior border.

MRI ORBITS PLANNING OF AXIAL SCANS

Parameters

TR

4000-6000

TE

68
110

FLIP

180

NXA

1    2

SLICE

3MM

MATRIX

192X192

FOV

180-200

PHASE

R>L

GAP

10%

B VALUE

50
1000

T2 tse sagittal oblique RT

Plan the sagittal slices on the axial plane and angle the planning block parallel to the optic nerve. Check the planning block in the other two planes. An appropriate angle must be given in the coronal plane, parallel to the line along the right (RT) superior and RT inferior rectus muscles. Ensure that the slices are sufficient to cover the right (RT) orbit.

MRI ORBITS PLANNING OF SAGITTAL

Parameters

TR

3000-4000

TE

100-120

SLICE

3 MM

FLIP

130-150

PHASE

A>P

MATRIX

256X256

FOV

150-170

GAP

10%

NEX(AVRAGE)

3

T2 tse sagittal oblique LT

Plan the sagittal slices on the axial plane and angle the planning block parallel to the optic nerve. Check the planning block in the other two planes. An appropriate angle must be given in the coronal plane, parallel to the line along the left (LT) superior and LT inferior rectus muscles. Ensure that the slices are sufficient to cover the LT orbit.

MRI ORBITS PLANNING and protocol of sagittal left side

Parameters

TR

3000-4000

TE

100-120

SLICE

3 MM

FLIP

130-150

PHASE

A>P

MATRIX

256X256

FOV

150-170

GAP

10%

NEX(AVRAGE)

3

For contrast enhanced scans

Post-contrast scanning will only be performed if any pathology is observed in the pre-contrast scans

For post-contrast orbit imaging, please use T1 SE fat-saturated axial and coronal small FOV sequences after the administration of IV gadolinium DTPA injection (copy the planning outlined above). The document below provides access to the recommended dosage of gadolinium DTPA injection, as advised by the manufacturer.