MRI Brain Protocol & Technique

 

MRI Brain Protocol & Technique

What is MRI

Magnetic resonance imaging (MRI) is a test that uses a magnetic field and pulses of radio wave energy to make pictures of organs and structures inside the body. In many cases, MRI gives different information about structures in the body than can be seen with an X-ray, ultrasound, or computed tomography (CT) scan.

How it Work

The human body is mostly water. Water molecules (H20) contain hydrogen nuclei (protons), which become aligned in a magnetic field. An MRI scanner applies a very strong magnetic field (about 0.2 to 3 tesla  or roughly a thousand times the strength of a typical fridge magnet), which aligns the proton "spins."

Before the imaging start, the hydrogen atom inside your body Are aligned in random Direction.

A Super conducting magnet creates a strong magnet field that aligns all the hydrogen protons in your body in same direction.

Radio waves are transmitted through your body the waves jostle the proton a bit of their axis and spin Them in the same direction.

When the radio waves are turned off, the protons return their aligned positions. The time it takes for the ions to return to their alignment is measured by the scanner. Different tissues each have unique time fame. A computer uses this data to assemble a detail image of your body.

 

Preparation of patient

ž  Before an MRI exam, eat normally and continue to take your usual medications, unless otherwise instructed. You will be asked to change into a gown and to remove following as :

ž  Jewelry

ž  Hairpins

ž  Eyeglasses

ž  Watches

ž  Wigs

ž  Dentures

ž  Hearing aid

ž  Under  garments

                               And

Check the Serum creatinine with calculation of eGFR should be performed in patients with any of the following risk factors:

ž  Fix  IV cannula

ž  If possible practice the patient to breath hold before examination.

ž  Explain the patient that it is a long procedure; it will take 45-50 min .So pass out urine and be comfortable.

ž  Sign  the consent form  for all routine and contrast study

 

Contraindications for MRI

Cardiac pacemakers.

Cochlear implants.

     Neurostimulator

     Artificial heart valves

     Pregnancy- Avoid MRI in 1^st trimester of pregnancy

Exposure of metal fragments to your eye or History as a metal worker.

 

 

Role of MRI technologist

MRI technologist to perform the proper test requested by a doctor. An MRI technologist positions patients correctly and operates MRI equipment to produce clear images of bones, organs, and other soft tissues. A technologist also communicates with the patient via an audio speaker to relay any instructions while the MRI is being conducted. While an MRI technologist does not evaluate images for a patient, he or she typically supplies written reports about the images to the requesting doctor. In some cases, an MRI technologist might be responsible for performing routine maintenance tests on MRI equipment and schedule repairs as needed.

 BRAIN & SKULL

 

Position of patient: Supine 

Fix the head by soft pad in the head coil

Supporting pad fix just below the legs.

Centering on glabella

Offer the patient ear plugs & ear protector or Music

Sequence- 

Survey three plane

Transverse- DWI, T2, T2Flair, T1, PD, Gradient

Coronal    - T2, T2 Flair

Sagittal   - T2, T2 Flair

Post Contrast -T1 Fat sat & T13D

 

Indication- stroke, epilepsy, tumor, multiple sclerosis, dementia, post-trauma, metabolic disorders, nerve palsies, Headache, Giddiness, Vertigo , Tinnitus. Seizer Disorder

Planning transverse: Transverse plan on sagittal image box Line parallel to genu of corpus callosum and check the plan other planes with appropriate angle. Coverage of brain foramen magnum to vertex.

T2 TSE Scan parameters

FOV -220-=240	TE – 90	TR 3500-5000	Matrix 512X384
Flip angle90-100	Slice thickness 4-5 mm	Gap -10 % of slice thickness	Fold over Direction – RL
NEX 2	Saturation band parallel to the slice

 

 

 

 

Diffusion Transverse

FOV -220-=240	TE – 80-120	TR 2500-4000		Matrix 192X192
Flip angle90-100	Slice thickness 4-5 mm	Gap -10 % of slice thickness		Fold over Direction – AP
NEX 2	B Value-1000		Saturation band parallel to the slice

 

T2 Flair Transverse

FOV -220-=240	TE – 90		TR 3000-11000	Matrix 384X292
Flip angle90-120	Slice thickness 4-5 mm		Gap -20 % of slice thickness	Fold over Direction – RL
NEX 2	IR Delay 1600-3000	Saturation band parallel to the slice

 

 

T1 TSE Transverse

FOV -220-=240	TE – 20	TR 400-700	Matrix 384X292
Flip angle90-100	Slice thickness 4-5 mm	Gap -10 % of slice thickness	Fold over Direction – RL
NEX 2	Saturation band parallel to the slice

 

 

 

 

 

Gradient (GRE)

FOV -220-=240	TE – 20 (in phase)	TR 500-700	Matrix 384X292
Flip angle20-30	Slice thickness 4-5 mm	Gap -20 % of slice thickness	Fold over Direction – RL
NEX 2	Saturation band parallel to the slice

 

PD Transverse (Proton density)

FOV -220-=240	TE – 20 (in phase)	TR 2500-4000	Matrix 384X292
Flip angle90-100	Slice thickness 4-5 mm	Gap -20 % of slice thickness	Fold over Direction – RL
NEX 2	Saturation band parallel to the slice

 

Planning coronal

Plan on sagittal image, box Line perpendicular to corpus callosum or parallel to medulla check the plan other planes with appropriate angle.

Coronal T2 Parameters

FOV -220-=240	TE – 90	TR 3500-5000	Matrix 512X384
Flip angle90-100	Slice thickness 4-5 mm	Gap -10 % of slice thickness	Fold over Direction – FH
NEX 2	Saturation band parallel to the slice

 

Sagittal

Plan on coronal image, box Line parallel to corpus callosum check the plan other planes with appropriate angle.

Sagittal T2Flair Parameters

FOV -220-=240	TE – 90		TR 3000-11000	Matrix 384X292
Flip angle90-120	Slice thickness 4-5 mm		Gap -20 % of slice thickness	Fold over Direction – AP
NEX 2	IR Delay 1600-3000	Saturation band parallel to the slice

 

INNER EAR (IAMS)

Indication: Trigeminal neuralgia, Tinnitus, Vertigo. Hearing loss.

Sequence: 3D BTFE, 3DCISS, 3D FIESTA

Plan on coronal image Block parallel to the line along right and left IAMS. Check the plan other planes with appropriate angle.

Parameters 3D Transverse

FOV -150-=180	TE – 10		TR 15	Matrix 384X292
Flip angle50-90	Slice thickness 0-5 mm		Gap -0	Fold over Direction – RL
NEX 2		Saturation band parallel to the slice

 

Coronal T2 3D

Coronal: Coronal plan on Transverse image Block parallel to the line along right and left IAMS. Check the plan other planes with appropriate angle.

Parameters

FOV -150-=180	TE – 150- 190		TR 1200-1800	Matrix 512X384
Flip angle 90	Slice thickness 0-5 mm		Gap -0	Fold over Direction – FH
NEX 2		Saturation band parallel to the slice

 

 

 

Hippocampus (Epilepsy)

Coronal oblique: Coronal oblique plan on sagittal image Block line perpendicular to hippocampus and check appropriate angle two other planes.

T1 IR Coronal oblique Parameters

FOV -150-180	TE – 8- 10		TR 2200-2700	Matrix 384X292
Flip angle 90-120	Slice thickness 3 mm		Gap -0	Fold over Direction – FH
NEX 2	IR Delay 350-450	Saturation band parallel to the slice

 

T2 Flair Coronal oblique Parameters

FOV -150-180	TE – Min-20		TR 3000-11000	Matrix 512x384
Flip angle 90-120	Slice thickness 3 mm		Gap -0	Fold over Direction – FH
NEX 2	IR Delay 1600-3000	Saturation band parallel to the slice

 

3D Flair: Sagittal

FOV -220-240	TE – Min-20		TR 4500-6000	Matrix 512x384
Flip angle 90-120	Slice thickness 0.5 mm		Gap -0	Fold over Direction – AP
NEX 2	IR Delay 1600-1700	Saturation band parallel to the slice

 

3D DIR (Dual inversion Recovery)  Sagittal

FOV -220-240	TE – Min		TR 4500-6000	Matrix 208X208
Flip angle 90-120	Slice thickness 0.5 mm		Gap -0	Fold over Direction – AP
NEX 2	1)IR Delay 2250 2)450	Saturation band parallel to the slice

 

Orbit

Indication

orbital tumours, followed by inflammatory disease and then thyroid disease.

Position:

Position of patient: Supine 

Fix the head by soft pad in the head coil

Supporting pad fix just below the legs.

Centering on glabella

Offer the patient ear plugs & ear protector or Music

Sequence- Survey three plane

 

Sequence

Coronal -T2,T2FS,T1

Sagittal -T2,T2FS,T1

Transverse –T2, T2FS, T1,T1FS

Position of patient: Supine 

Fix the head by soft pad in the head coil

Supporting pad fix just below the legs.

Centering on glabella

Offer the patient ear plugs & ear protector or Music

Sequence- Survey three plane

 

Transverse T2: Transverse plan on sagittal image Block line  parallel to the line along right and left Optic Nerve and check appropriate angle two others plane.

 

Parameters

FOV 150-180	TE 90-120		TR 3500-5000	Matrix 384X292
Flip angle 90-100	Slice thickness 2-3 mm		Gap -10 % of slice thickness	Fold over Direction – RL
NEX 2		Saturation band parallel to the slice

 

 

  T1 TSE Transverse

FOV 150-180	TE 0-20		TR 400-700	Matrix 384X292
Flip angle 90-100	Slice thickness 2-3 mm		Gap -10 % of slice thickness	Fold over Direction – RL
NEX 2		Saturation band parallel to the slice

 

.

Coronal

Coronal plan on sagittal image Block line Block Perpendicular to the Optic Nerve and parallel to right and left eye lenses and check appropriate angle two others plane.

 

Parameters

FOV 150-180	TE 90-120		TR 3500-5000	Matrix 384X320
Flip angle 90-120	Slice thickness 2-3 mm		Gap -10 % of slice thickness	Fold over Direction – RL
NEX 2		Saturation band perpendicular to the slice & inferior to plan.

 

 

Sagittal T2

Sagittal plan on transverse image Block line parallel to Optic nerve and check appropriate angles others two plane. 

FOV 150-180	TE 90-120		TR 3500-5000	Matrix 384X320
Flip angle 90-120	Slice thickness 2-3 mm		Gap -10 % of slice thickness	Fold over Direction – AP
NEX 2		Saturation band perpendicular to the slice & inferior to plan.

 

 

 

 

 

PNS / CYSTERNOGRAPHY

Indications for the exam are: normal pressure hydrocephalus, Pseudotumor  Cerebri, and the evaluation of ventricular shunting tubes .Sinusitis.

Position of patient: Supine 

Fix the head by soft pad in the head coil

Supporting pad fix just below the legs.

Centering on glabella

Offer the patient ear plugs & ear protector or Music

Sequence- Survey three plane

Coronal- T2,T2FS,T1,BTFE 3D

Transverse-T2,T2FS,Transverse,STIR

Sagittal-T2 T2FS

 

Coronal T2- Block line perpendicular to hard plate & check the position on two other plane (coverage of whole sinus). 

T2 Coronal

FOV 150-180	TE 90-120		TR 3500-5000	Matrix 384X320
Flip angle 90-120	Slice thickness 2-3 mm		Gap -10 % of slice thickness	Fold over Direction – FH
NEX 2		Saturation band perpendicular to the slice & inferior to plan.

 

 

 

 

 

 

 

 

T1 TSE Transverse

 Axial plan on sagittal or coronal, Block line parallel to hard plate and check plan on other planes with appropriate angle.

Coronal T1 TSE Transverse

FOV 150-180	TE 0-20		TR 400-700	Matrix 384X292
Flip angle 90-100	Slice thickness 2-3 mm		Gap -10 % of slice thickness	Fold over Direction – RL
NEX 2		Saturation band parallel to the slice

 

 

 

 

 

 

 

 

 

Sella (Pituitary fosa)

Position of patient: Supine 

Fix the head by soft pad in the head coil

Supporting pad fix just below the legs.

Centering on glabella

Offer the patient ear plugs & ear protector or Music

Sequence- Survey three plane

Transverse T2 full brain coverage

Sequence  Coronal T2,T1

Sagittal  T2,T1

Sagittal T2 :

 

 

Coronal- Line parallel to sella on axial image and check plan on other two planes.

 

T2 Scan parameters

FOV 150-180	TE 90-120		TR 3500-5000	Matrix 384X320
Flip angle 90-120	Slice thickness 2-3 mm		Gap -10 % of slice thickness	Fold over Direction – RL
NEX 2		Saturation band perpendicular to the slice & inferior to plan.

 

 

Sagittal - Position blocks perpendicular to sella on transverse image and check the other two planes.

Sagittal T1

FOV 150-180	TE Min-20		TR 400-700	Matrix 320x292
Flip angle 90-120	Slice thickness 2-3 mm		Gap -10 % of slice thickness	Fold over Direction – AP
NEX 2		Saturation band perpendicular to the slice & inferior to plan.

 

 

CORONAL DYNAMIC  PLAN 

Coronal-T1

FOV 150-180	TE Min-15		TR 400-700	196x156
Flip angle 90-120	Slice thickness 1-1.5mm		Gap -10 % of slice thickness	Fold over Direction – FH
NEX 1		Saturation band perpendicular to the slice & inferior to plan.

 

 

Temporo-mandibular joint

Position of patient: Supine 

Fix the head by soft pad in the head coil

Supporting pad fix just below the legs.

Centering on glabella

Offer the patient ear plugs & ear protector or Music

 

Sequence- Survey three plane

Coronal- T2,PD,T1, Stir

Coronal - Block line parallel to condoyle of mandible (left & right)

FOV 80-100	TE 90-120		TR 3500-5000	Matrix 384X320
Flip angle 90-120	Slice thickness 2 mm		Gap  0	Fold over Direction – RL
NEX 2		Saturation band perpendicular to the slice & inferior to plan.

 

Sagittal-

Box line parallel to hard plate on sagittal image and check the plan box other two planes.

 

Sagittal- PD

FOV 150-180	TE 15-30		TR 200-2500	Matrix 288x244
Flip angle 90	Slice thickness 2 mm		Gap -10 % of slice thickness	Fold over Direction – AP
NEX 2		Saturation band perpendicular to the slice & inferior to plan.

 

Axial plan- Block line parallel to hard plate on sagittal image and check appropriate angle on other planes.

FACE

Position of patient: Supine 

Fix the head by soft pad in the head coil

Supporting pad fix just below the legs.

Centering on glabella

Offer the patient ear plugs & ear protector or Music

Sequence- Survey three plane

Coronal- T2, T1, STIR

 

 Transverse-T2, T1, STIR, DWI

Sagittal-STIR, T1, T2

 

Coronal - T2- Block line perpendicular to hard plate on sagittal image & check the position on two other planes.

 

 

Axial plan

Block line parallel to hard plate on sagittal image & check the position on two other planes with appropriate angle.

 

 

Sagittal plan –

Block line parallel to nasal septum on coronal or axial images   & check the position on other sagittal plane with appropriate angle.

 

TRACTROGRAPHY

Position of patient: Supine 

Fix the head by soft pad in the head coil

Supporting pad fix just below the legs.

Centering on glabella

Offer the patient ear plugs & ear protector or Music

 

Sequence- Survey three plane

 

Sequence- 3D FLAIR, 3D T1,DTI

Block line parallel to genu of corpus callosum on sagittal image or check block position on other two planes. 

Scan parameter DTI (Diffusion Tenser Imaging)

FOV -220-=240	TE Shortest	TR Shortest		Matrix 112x112
Flip angle 90	Slice thickness 2 mm	Gap -0		Fold over Direction – AP
NEX 1	B Value-1000		Saturation band parallel to the slice

 

 

 

3D Transverse Flair scan parameters

FOV -220-240	TE – Min-20		TR 4000-6000	Matrix 204x204
Flip angle -	Slice thickness 0.5 mm		Gap -0	Fold over Direction – RL
NEX 2	IR Delay 1600-1700	Saturation band parallel to the slice

 

3D Transverse T1 scan parameters

FOV -220-240	TE – Min-20		TR - Min	Matrix 256x244
Flip angle -	Slice thickness 0.5 mm		Gap -0	Fold over Direction – RL
NEX 2	IR Delay 1000	Saturation band parallel to the slice

 

 

 

 

 

 

 

CST Mapping

FUNCTIONAL

Position of patient: Supine 

Fix the head by soft pad in the head coil

Supporting pad fix just below the legs.

Centering on glabella

Offer the patient ear plugs & ear protector or Music

 

Sequence- Survey three plane

3D Flair, 3DT1 , Bold

 

 

Planning – Axial full brain coverage.

Block line parallel to genu of corpus callosum on sagittal image or check block position on other two planes. 

Scan parameters Bold  –

FOV -220-=240	TE-  35	TR -3000		Matrix 96x96
Flip angle 90	Slice thickness 2 mm	Gap -0		Fold over Direction – AP
NEX 1	Dynamic - 60		Saturation band parallel to the slice

 

 

3D Transverse Flair scan parameters

FOV -220-240	TE – Shortest		TR 4000-6000	Matrix 204x204
Flip angle -	Slice thickness 0.5 mm		Gap -0	Fold over Direction – RL
NEX 2	IR Delay 1600-1700	Saturation band parallel to the slice

 

3D Transverse T1 scan parameters

FOV -220-240	TE – Min-20		TR - Min	Matrix 256x244
Flip angle -	Slice thickness 0.5 mm		Gap -0	Fold over Direction – RL
NEX 2	IR Delay 1000	Saturation band parallel to the slice

 

 

 

 

 

 

 

 

 

Process images 

Perfusion – Brain

Position of patient: Supine 

Fix the head by soft pad in the head coil

Supporting pad fix just below the legs.

Centering on glabella

Offer the patient ear plugs & ear protector or Music

 

Sequence- Survey three plane, T2 Star Perfusion.

 

Planning – Axial full brain coverage.

Block line parallel to genu of corpus callosum on sagittal image or check block position on other two planes. 

T2* Perfusion scan parameters

3D Transverse T1 scan parameters

FOV -220-240	TE – Min-40		TR - Shortest	96x96
Flip angle - 75	Slice thickness 4-5 mm		Gap -0	Fold over Direction – AP
NEX 2	Contrast -20ml volume-5ml/sec	Saturation band parallel to the slice

 

 

CSF STUDY FOR BRAIN

Position of patient: Supine 

Fix the head by soft pad in the head coil

Supporting pad fix just below the legs.

Centering on glabella

Offer the patient ear plugs & ear protector or Music

 

Sequence- Survey three plane, Q-flow, 3D Flair, 3DT1, PD, PCA

Planning – Planning line perpendicular to aqua duct on sagittal image and check the appropriate angle other plane

Planning Q-Flow

3D Transverse T1 scan parameters

FOV -220-240	TE – Min-40		TR - Shortest	96x96
Flip angle - 75	Slice thickness 4-5 mm		Gap -0	Fold over Direction – AP
NEX 2	Contrast -20ml volume-5ml/sec	Saturation band parallel to the slice

 

3D Transverse T1 scan parameters

FOV -220-240	TE – Min-20		TR - Min	Matrix 256x244
Flip angle -	Slice thickness 0.5 mm		Gap -0	Fold over Direction – RL
NEX 2	IR Delay 1000	Saturation band parallel to the slice

 

 

Spectroscopy

Position of patient: Supine 

Fix the head by soft pad in the head coil

Supporting pad fix just below the legs.

Centering on glabella

Offer the patient ear plugs & ear protector or Music

 

Sequence- Survey three plane,

Multi Voxel -

Axial T2 Survey

1.    The MRI Technologist will plan the spect voxels.  Typically they will want one on whatever lesion they are looking at, and one in normal healthy white matter.

2.    Voxel sizes: maximum 20 x 20 x 20, but you can go as small as 10 x 10 x 10.

3.    Make every effort possible to avoid placing any part of the voxels inside CSF, bone, or air.  You may turn the voxel boxes in any direction to help achieve this.

Transverse Multi  Voxel spectroscopy(PRESS)  scan parameters

Voxel size -10x10	TE – Min-144		TR – 2000-2200	Matrix 22x22
Flip angle -			Gap -0	Fold over Direction – RL
NEX 2	Spectral Band width -2000	Saturation band circular 10

 

 

Single voxel Spectroscopy –

1.    The MRI Technologist will plan the spect voxels.  Typically they will want one on whatever lesion they are looking at, and one in normal healthy white matter.

2.    Voxel sizes:  10 x 10 x 10.

3.    Make every effort possible to avoid placing any part of the  voxelss inside CSF, bone, or air.  You may turn the voxel boxes in any direction to help achieve this.

Transverse Single   Voxel spectroscopy (PRESS)   scan parameters

Voxel size -10x10	TE – Min-144		TR – 1200	Matrix 835x53
Flip angle -			Gap -0	Fold over Direction – RL
NEX 2	Spectral Band width -2000	Saturation band

Published by:

Dr Ravi Dutt Sharma. Jaypee Healthcare .Department of Radiodiagnosis Noida