High Field Spine Imaging

Department of Radiology
University of California
San Diego
3T for MR Applications
Advantages
High Field Spine Imaging

Increased signal-to-noise

Better fat suppression

Increased enhancement with gadolinium

Definite measurable benefits for MRS,
John R. Hesselink, M.D.
MRA, & Diffusion tensor imaging
3T for Spine Imaging
Problems
3T for Spine Imaging
Problem
1.
Increased SAR
with FSE)
2.
Increased chemical shift
3.
Decreased T1 contrast
4.
Increased susceptibility
5.
Dielectric effects
6.
More flow artifacts
7.
Increased gradient noise (130 dB)
8.
Increased cost of purchase & maintenance
Increased
chemical shift
3T for Spine Imaging
Problem
Trade-offs
Solutions
1. Parallel imaging
2. Shaped RF waveforms
3. Flip angle for
acquisition rf pulses
4. ETL, TR
5. 3D acquisition
–
–
–
None, scan time
None
Minimal
–
–
Scan time
Scan time but
SNR
1. Bandwidth
2. FOV, Matrix
3. Fat saturation
–
–
–
SNR but min TE
SNR but resolution
SAR & may scan
time
3T for Spine Imaging
Trade-offs
Problem
More flow
Artifacts
Gray CSF on
T1 images
1. Reduce flip angle
2. T1 FLAIR
–
–
Minimal
Minimal
Increased
Susceptibility
1. Bandwidth
2. Matrix & FOV &
slice thickness
3. Parallel imaging
4. TE for T1WIs
–
–
SNR but
SNR but
–
–
None, scan time
Better, SNR
1. High electric
permittivity pads
2. Multi-transmit RF
–
Cumbersome
–
None
Dielectric effects
Solutions
Increased SAR (Large FOV met surveys
Proc. Intl. Soc. Mag. Reson. Med. 20 (2012)
Solutions
Trade-offs
1. Sat pulses
–
2. Change phase
direction
3. Use gradient-echo
–
SAR & may scan
time
May scan time
–
SNR
Increased
gradient noise
1. Better ear plugs
2. Acoustically shielded
bore liners
–
–
Cost
Cost
Increased cost
of magnet &
maintenance
1. Hire the Terminator
as your negotiator
–
???
min TE
resolution
3T Spine Imaging
Parallel Imaging
C-Spine Sequences
Decreases SAR, Susceptibility, Distortion
32 channels
102 coil elements
Siemens TIM Trio
8 channel ASSET Brain
8 channel ASSET NeuroVas
8 channel CTL Spine coil
16 channel ASSET HeadNeck-Spine Array (29 e)
8 channel SENSE™ Head coil
16 channel SENSE™ NeuroVas
12 element CTL Spine coil
6 channel SENSE™ Torso coil
•
T2 FSE
All manufacturers have 8 channel systems, moving toward 16 & 32
T1 FSE
T1 FLAIR
Acc - 2907739
3T Spine Imaging
3T Spine Imaging
Cervical Axial Sequences
Cervical Axial Sequences
T2 FSE
T2 3D FRFSE
Acc 2754310
3T Spine Imaging
Cervical Axial Sequences
COSMIC
T2 GRE
Acc 2520822
FIESTA / 3D CISS
Acc 999999
Proc. Intl. Soc. Mag. Reson. Med. 20 (2012)
T2 FSE
GRE - MERGE
Acc - 3083429
3T Spine Imaging
Post Gd Sequences
T1 with Gad & FS
Acc 2753035
3T Spine Imaging
3T Spine Imaging
Disk Extrusion
Demyelinating Disease
OSP Ballaria, Bologna, Italy
NeuroSkeletal Imaging, Florida
Acc 1834440
3T Spine Imaging
3T Spine Imaging
Susceptibility Artifact – Hardware
Post-op Cervical Spine
Increase Bandwidth, Frequency SI / RL, Avoid GRE & Fat Suppression
Acc -
IDEAL Contrast:
Iterative Decomposition of Water and
Fat With Echo Asymmetry and Least-Squares Estimation
water
fat
Cervical Spine:
Neurofibromatosis
Acquired Data
Echo 1,
TE= - /6
Iterative
Reconstruction
Water Only
Fat Only
In-phase
Out-of-phase
Echo 2,
TE= /2
Echo 3,
TE= 7 /6
T1W Fat Sat FSE
T1W IDEAL-FSE
18 /
*Reeder et al. MRM, 54:636–644 (2005)
Proc. Intl. Soc. Mag. Reson. Med. 20 (2012)
GE /
Courtesy Scott Reeder
UW-Madison
3T Spine Protocols
3T Spine Imaging
Cervical Spine
Thoracic Spine
Sequence
TR/TE/ET/NEX
Sagittal T2 FSE
4000/110/24/4
FOV
Slice
Matrix
22
3/0.5
448x224
SI
31.2
24
3/0.5
384x224
SI
41.7
Sagittal STIR
3200/24/12/3/TI-150 24
3/0.5
384x224
SI
31.2
Axial T2 FSE
4500/120/21/4
3/1
448x224
AP
41.7
Sagittal T1 FLAIR 3300/9/8/2/TI-1230
20
Phase Bandwidth
Axial T2 FRFSE
2200/100/39/1
18
2.5/0
320x224 AP&RL 41.7
Axial MERGE
450/11/1/2/20deg
20
3/0.5
320x192
AP
41.7
Sag T1 FSE Gd
600/11/4/3
24
3/1
384x224
AP
31.2
Axial T1 FSE Gd 700/10/3/3
24
3/1
384x224
AP
31.2
T2 FSE
T1 FSE
T1 FLAIR
Acc
3T Spine Imaging
Metastases
T1 FLAIR
at 3 T
Thoracic Spine
T2 FSE
T1 FLAIR
T1-Gd-FS
Courtesy: Meng Law, Mount Sinai, NY
Acc -
3T Spine Imaging
3T Spine Imaging
Sagittal T2 & T1 FSE
Sagittal Lumbar Spine
T2 FSE
T1 FSE
Acc 2505606
Proc. Intl. Soc. Mag. Reson. Med. 20 (2012)
T2 FSE
T1 FSE
T1 FLAIR
Acc 2789831
3T Spine Imaging
3T Spine Imaging
Phase-artifacts & Chemical Shift
Phase – Frequency Direction
Phase AP
Phase SI
Acc
3T Spine Imaging
3T Spine Imaging
Effect of Vacation
Sagittal T2 FSE
No SAT Bands, Phase AP, Low Matrix
Acc
T2 FSE
3T Spine Imaging
3T Spine Imaging
3T MR-Cat Scan Fusion
Axial Lumbar
Sequences
T1 FSE
T1 FLAIR
T2 FSE
Acc
Proc. Intl. Soc. Mag. Reson. Med. 20 (2012)
T1 FSE
Acc 2772226
3T Spine Imaging
3T Spine Imaging
Phase-artifact Reduction
Lumbar Disk Protrusion
Crossed SAT Bands (Vision)
T2 FSE
3T Spine Imaging
T1 FSE
3T Spine Imaging
Proton-Density Axial
No Coil – No Signal
Series 1
T2 FSE
T1 FSE
3T Spine Imaging
Post-Gd T1 with FS
Acc 2511067
Proc. Intl. Soc. Mag. Reson. Med. 20 (2012)
T1 FLAIR
PD FSE
Series 2
Acc 2793235
1.5T Spine Imaging
Post-op Lumbar Spine
Acc
3T Spine Imaging
1.5T Spine Imaging
Post-op Lumbar Spine
Post-op Lumbar Spine
Acc
3T Spine Imaging
Acc
History: 32 y/o male with back & leg pain
Post-op Lumbar Spine
Dx: Spinal stenosis
Acc
3T Spine Imaging
3T Spine Imaging
Disk Protrusion
Disk Extrusion
Acc -
Proc. Intl. Soc. Mag. Reson. Med. 20 (2012)
Acc -
3T Spine Imaging
Multiple Sclerosis
{Page 2}
Acc -
{Page 2}
History: 43 y/o man with
back pain for several months
Dx: Hemangioblastoma
553 –CV
History: 36 y/o man with a chronic C6-8 radiculopathy
{Page 2}
Dx: Spinal dural AVM
620 -
Proc. Intl. Soc. Mag. Reson. Med. 20 (2012)
3T Spine Protocols
History: 95 y/o woman with acute
bilateral upper extremity weakness
Lumbar Spine
Sequence
TR/TE/ET/NEX
Sagittal T2 FSE
4000/120/27/4
Sagittal T1 FLAIR 3000/30/8/2/TI-958
FOV
Slice
Matrix
Phase Bandwidth
26
3.5/0.5 448x224
SI
41.7
28
3/0.5
SI
41.7
Sagittal STIR
3500/24/12/3/TI-150 26
Axial T2 FSE
4500/120/21/4
448x224
3.5/0.5 384x224
20
3/1
448x224
SI
31.2
AP
41.7
Axial T1 FSE
600/10/4/2
20
3/1
320x224
AP
31.2
Axial PD FSE
3000/11/4/2
20
3/1
448x224
AP
31.2
Sag T1 FSE Gd
517/8/4/4
3.5/0.5 320x224
AP
31.2
AP
31.2
26
Axial T1 FSE Gd 600/10/4/2
20
MRA FSPGR Gd
40
7.1/2.9/1/35deg
3/1
320x224
1.6/0.4 416x224
AP-RL 41.7
30 ml @ 3ml/sec
Dx: Acute cord infarction
746 - 05121249
History: 48 y/o women with pain down both legs
{Page 2}
DWI - ADC
Dx: Spinal epidermoid
747 - 07057664
Proc. Intl. Soc. Mag. Reson. Med. 20 (2012)