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Advances in Neuroimaging at 3 T
American Society of Neuroimaging 2013
American Society of Neuroimaging36th Annual Meeting
Dr. Mark WinklerSteinberg Diagnostic Medical Imaging
Las Vegas, Nevada USA
• Dr. Mark Winkler is on the Medical AdvisoryBoard for TOSHIBA America Medical Systems
DISCLOSURES
American Society of Neuroimaging36th Annual Meeting
Advances in Neuroimaging at 3 T
• Patient Friendly 3 T
• High Resolution Brain Imaging
• CSF Flow Imaging
• ASL Contrast Free Brain Perfusion
• Whole Body Imaging
• Contrast Free MRA
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Patient Friendly 3 T
• Shorter
• Wider
• Quieter
• A more CT‐like experience
Patient Friendly 3.0 T
• Shorter
– 240 cm → 175 cm
175cm
240cm
Patient Friendly 3 T
• Wider
– 60 cm → 71 cm
71cm
60cm
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Patient Friendly 3 T
• Quieter
– 3 T is 10 times louder (SPL) than 1.5 T
– Pianissimo reduces the noise by a factor of 30 (SPL)
G di h i ll i l d f h• Gradients are Mechanically isolated from the Magnet
• Gradients are enclosed in a Vacuum Chamber
– Improves patient Acceptance
• Open MRI gets the Patient in the scanner
• Quiet MRI keeps the Patient in for the scan
Patient Friendly 3 T• Quieter
– Reduces Vibratory Motion
• Improves High Resolution Images
• Avoids Motion Artifacts in Advanced Imaging
– DTI, fMRI, PWI and EPI in general
– Spectroscopy
– Flow related imaging techniques
High Resolution Neuro Imaging
• Increased SNR allows for high resolution 2D imaging with all techniques
• Alzheimer Disease Neuroimaging Initiative (ADNI) protocol includes(ADNI) protocol includes
– Dual echo
– FLAIR
– T1 SE
– T1 3D FFE
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Alzheimer Disease Neuroimaging Initiative
Dual Echo
DUAL PD/T2 (FSE TR/TE1/TE2 = 3750/18/90 ms, voxel = 0.8x0.9x3 mm, no gap) – 3:16 min
Alzheimer Disease Neuroimaging Initiative
T2 FLAIR
FLAIR (FSE TR/TE/TI = 9900/96/2700 ms, voxel = 0.8x0.8x3 mm, no gap) – 3:38 min
Alzheimer Disease Neuroimaging Initiative
T1 SE vs. T1 FSE IR
T1‐IR (SE TR/TE/TI = 2900/10/1100 ms, voxel =
0.8x0.8x3 mm, no gap) – 3:16 min
T1 (SE TR/TE = 700/10 ms, voxel = 0.8x0.8x3 mm, no
gap) – 4:16 min
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Alzheimer Disease Neuroimaging Initiative
T1 3D IR‐FFE
T1 3D IR‐FFE (TR/TE/TI = 8.8/3.2/450 ms, voxel = 1x1x1 mm,) – 4:04 min
High Resolution Neuro Imaging
• Increased SNR allows for 3D Isotropic Imaging with all Techniques
– T1
T2– T2
– FLAIR
– T2 SSFP
High Resolution Neuro Imaging3D IR‐FFE T1W
3D IR-FFE, TR/TE/FA = 18/5.5/20, matrix=240 x 240, FOV=24x24cm, 360 slices
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High Resolution Neuro Imaging3D FSE T2W
High Resolution Neuro Imaging3D FSE FLAIR
Advances in 3 T MRIT2 3D SSFP
3D SSFP (0.4x0.4 mm x 0.8 mm)
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Advances in 3 T MRIT2 3D SSFP
3D SSFP (0.4x0.4 mm x 0.8 mm)
CSF Flow
• Normal CSF Flow
− Pulsatile
− Bidirectional
/ f− Bulk/Net forward Flow
• Normal Pressure Hydrocephalus (NPH)
• Aqueductal Stenosis
• Chiari Malformation
Normal CSF Flow
• CSF Exchange between the Lateral and the 3rd
Ventricles through the Foramen of Monro
Chair Dr. Shinya YamadaTokai UniversityTOSHIBA Advanced CSF Discussion Group
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Normal CSF Flow
• CSF Exchange between the Lateral and the 3rd
Ventricles through the Foramen of Monro
Chair Dr. Shinya YamadaTokai UniversityTOSHIBA Advanced CSF Discussion Group
• Pulsatile CSF Movement between the 3rd and the 4th
Ventricles through the Aqueduct of Sylvius
NPH
• No CSF Exchange between the Lateral and the 3rd
Ventricles through the Foramen of Monro (Functionally a
M V t i l )
Chair Dr. Shinya YamadaTokai UniversityTOSHIBA Advanced CSF Discussion Group
Mono‐Ventricle)
NPH
• No CSF Exchange between the Lateral and the 3rd
Ventricles through the Foramen of Monro (Functionally a
M V t i l )
Chair Dr. Shinya YamadaTokai UniversityTOSHIBA Advanced CSF Discussion Group
Mono‐Ventricle)
• Hyperdynamic CSF Movement between the 3rd
and the 4th Ventricles through the Aqueduct of Sylvius
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• May Restore CSF Exchange between the Lateral and the 3rd Ventricles through the Foramen of Monro
Shunted NPH
Chair Dr. Shinya YamadaTokai UniversityTOSHIBA Advanced CSF Discussion Group
Exclusion of NPH
• Normal CSF Exchange between the Lateral Ventricles and the 3rd Ventricle excludes NPH
Chair Dr. Shinya YamadaTokai UniversityTOSHIBA Advanced CSF Discussion Group
ASL Contrast Free Perfusion
• Tag Inflowing Blood
• Non‐Contrast Exam
• More Accurate than Dynamic Susceptibility C (DSC) P f iContrast (DSC) Perfusion
– DSC can under/over estimate Perfusion
– GAD related BBB Breakdown Artifacts
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ASL Contrast Free Perfusion• Tumor Perfusion
• Radiation Necrosis
• More accurate than DSC Perfusion
But also
• Ischemia/Stroke
• Cognitive Disorders/Dementia Workups
Perfusion Imaging by ASLLymphoma
Post‐ContrastDSC‐CBF
Non‐ContrastASL‐CBF
T1W post‐GAD
Courtesy of Dr. Kazuhiro TsuchiyaKyorin University
Perfusion Imaging by ASLMeningioma
Courtesy of Dr. Kazuhiro TsuchiyaKyorin University
Non‐Contrast ASL‐CBFT1W post‐GAD
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Perfusion Imaging by ASLRadionecrosis
T1W post‐GAD
Courtesy of Dr. Kazuhiro TsuchiyaKyorin University
Post‐ContrastDSC‐CBF
Non‐ContrastASL‐CBF
Perfusion Imaging by ASLOligodendroglioma
T1W post‐GAD
Courtesy of Dr. Kazuhiro TsuchiyaKyorin University
Post‐ContrastDSC‐CBF
Non‐ContrastASL‐CBF
Advanced 3 T Whole Body Imaging
• Multi‐phase Multi‐port (MP‐MP) Transmission
• Homogeneous Fat Suppression
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• Two RF Amplifiers
• Four RF Transmitters
• Homogeneous RF
Multi‐phase Multi‐port RF Transmission
• Homogeneous RF
• No Shading Artifact
• Multi‐phase Multi‐port RF Transmission does for Whole Body Imaging what 3 T has already done for Brain Imaging
Standard 3 T RF Transmission
• Dielectric (Shading) Artifact
Multi‐phase Multi‐port Transmission
• Eliminates Dielectric (Shading) Artifacts
In Phase FETR/TE=160/2.3 ms
Out of Phase FETR/TE=220/3.8 ms
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Multi‐phase Multi‐port Transmission
• Eliminates Dielectric (Shading) Artifacts
Standard MP-MP
Multi‐phase Multi‐port Transmission
• Eliminates Dielectric (Shading) Artifacts
FSE T2W Fat SatTR/TE=4200/80 ms
FSE T2WTR/TE=10000/90 ms
• Homogeneous Fat Suppression
– Magnet Homogeneity
– Magnet and Volume Shimming
• Slice Selective Fat Saturation
3 T Advanced Fat Saturation
Slice Selective Fat Saturation
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Global FatSat
Conventional vs. Slice Selective Fat Sat
(inhomogeneous)
Slice Selective FatSat(uniform)
Slice Selective Fat Sat3 T Fat Sat vs. STIR
FSE T2W Fat Sat FSE T2W STIR
Slice Selective Fat Sat3 T Abdominal Imaging
T2WI (FASE) Fat Sat T2WI FSE
Fat Sat T2WI
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• Fresh Blood Imaging
• ASL MR Angiography
• Dynamic ASL MR Angiography
Contrast Free Angiography
Arteries and Veins are High Signal
DIASTOLEArteries lose Signal from Dephasing
SYSTOLEArteries are Bright
SUBTRACTION
Fresh Blood ImagingPrinciples
Cardiac gated
Subtraction eliminates Veins
Fresh Blood ImagingRun‐off
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Fresh Blood ImagingDiabetes
ASL MR AngiographyPrinciples
DELAY
Respiratory gated
IR Pulse Suppresses VOI
Inflowing Blood is High Signal
IR delay Time determines the Phase of the Vascular Enhancement
ASL MR AngiographyRenal Arteries
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ASL MR AngiographyHepatic Venous Circulation
Dynamic ASL MR Angiography
The IR pulse delay is allowed to change dynamically
Sag TSA of Aneurism
Static 3D TOF
Bilateral MCA Occlusion
Dynamic ASL MRA
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• 3 T MRI continues to advance at a rapid pace
• More Patient Friendly
• New Applications
CSF Flow
Advances in 3 T MRI
–CSF Flow
–ASL Contrast Free Perfusion
–Contrast Free MRA
• Now does for Whole Body Imaging what it did for Brain Imaging
Thank youThank you