mrimaster

MRI Thumb : Protocol and Planning

Indications for thumb MRI scan

Contraindications

Patient preparation for thumb MRI scan

Positioning for thumb MRI scan

MRI hand positioning

Recommended Thumb MRI Protocols, Parameters, and Planning

Thumb MRI Localiser

A three-plane localizer must be taken at the beginning to localize and plan the sequences. Typically, these localizers take less than 25 seconds and can be achieved using T1 weighted low-resolution scans. It is advisable to obtain additional localizers until you have acquired accurate axial, coronal, and sagittal localizer images.

MRI thumb localiser image

Localiser 2

Plan a three-plane thumb localizer on the coronal and axial localizer images. Plan the thumb coronal localizer on the hand coronal localizer. Align the planning block parallel to the metacarpal and phalanx bones. Verify the planning in the axial localizer and align the block parallel to the long axis of the metacarpal bones.

Next, plan the thumb sagittal localizer on the axial plane and orient it perpendicular to the long axis of the metacarpal bones. Confirm the planning in the sagittal hand localizer and align it parallel to the metacarpal and phalanx bones.

Finally, plan the axial thumb localizer on the coronal hand localizer and position it perpendicular to the long axis of the metacarpal bone. Verify the positioning on the sagittal hand localizer and align it perpendicular to the long axis of the metacarpal bone.

T2 stir axial 3mm SFOV(80mm)

Plan the axial slices on the sagittal thumb localizer and position the planning block perpendicular to the metacarpal and phalanx bones. Check the positioning block in the other two planes. Use an appropriate angle in the coronal localizer, ensuring it is perpendicular to the metacarpal and phalanx bones. The slices should be sufficient to cover the entire thumb, from the fingertips to the carpometacarpal joint of the thumb.

Parameters

TR

5000-6000

TE

110

FLIP

150

NEX

3

SLICE

3MM

MATRIX

224×224

FOV

70-80

PHASE

A>P

GAP

10%

TI

160

Note:-An FOV ranging from 70mm to 80mm can only be achieved when utilizing a specialized high-channel wrist coil or conducting the scan within a 3T scanner. In cases where these choices are unavailable within your department, kindly opt for an FOV between 110mm and 130mm. The presented scans were executed using a 3T scanner equipped with deep resolution software.

T1 tse axial 3mm SFOV(80mm)

Plan the axial slices on the sagittal thumb localizer and position the planning block perpendicular to the metacarpal and phalanx bones. Check the positioning block in the other two planes. Use an appropriate angle in the coronal localizer, ensuring it is perpendicular to the metacarpal and phalanx bones. The slices should be sufficient to cover the entire thumb, from the fingertips to the carpometacarpal joint of the thumb.

Parameters

TR

400-600

TE

15-25

SLICE

3 MM

FLIP

150

PHASE

A>P

MATRIX

256X224

FOV

70-80

GAP

10%

NEX(AVRAGE)

3

T1 tse coronal 2mm SFOV(140X70mm)

Plan the coronal slices on the sagittal thumb localizer and angle the positioning block parallel to the metacarpal and phalanx bones. Check the positioning block in the other two planes. An appropriate angle must be used in the axial localizer, parallel to the long axis of metacarpal bones. The slices should be sufficient to cover the entire thumb, skin to skin. If available on your scanner, please use a smaller rectangular FOV of 70x140mm. In this case, use a phase direction from head to feet. If a rectangular FOV is not available, use a 140mm FOV with a right-to-left phase direction.

Parameters

TR

400-600

TE

15-25

SLICE

2 MM

FLIP

160

PHASE

H>F

MATRIX

256X256

FOV

70×140

GAP

10%

NEX(AVRAGE)

3

T2 stir coronal 2mm SFOV(140X70mm)

Plan the coronal slices on the sagittal thumb localizer and angle the positioning block parallel to the metacarpal and phalanx bones. Check the positioning block in the other two planes. An appropriate angle must be used in the axial images, parallel to the long axis of metacarpal bones. The slices should be sufficient to cover the entire thumb, skin to skin. If available on your scanner, please use a smaller rectangular FOV of 70x140mm. In this case, use a phase direction from head to feet. If a rectangular FOV is not available, use a 140mm FOV with a right-to-left phase direction.

Parameters

TR

3000-4000

TE

110

FLIP

150

NEX

3

SLICE

2 MM

MATRIX

256X224

FOV

70×140

PHASE

H>F

GAP

10%

TI

160

T2 stir sagittal 2mm SFOV(140X70mm)

Plan the sagittal slices on the coronal scans and angle the positioning block parallel to the metacarpal and phalanx bones. Check the positioning block in the other two planes. Ensure that an appropriate angle is used in the axial images, perpendicular to the long axis of the metacarpal bones. The slices should be sufficient to cover the entire thumb, from skin to skin. If a smaller rectangular FOV of 70x140mm is available on your scanner, please utilize it. In this case, use a phase direction from head to feet. If a rectangular FOV is not available, use a 140mm FOV with a right-to-left phase direction.

MRI thumb sagittal scan small FOV planning

Parameters

TR

3000-4000

TE

110

FLIP

150

NEX

3

SLICE

2 MM

MATRIX

256X224

FOV

70×140

PHASE

H>F

GAP

10%

TI

160