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Transcript of Dieter Meier Institute for Biomedical Engineering Future Trends in Clinical Diagnostics with...
Dieter Meier
Institute for Biomedical Engineering
Future Trends in Clinical Diagnostics with Magnetic
Resonance
SNHTA Bern 12. November 2003
Topics
• The “International Competence and Reference Center for MRI Methodology”
• Advantages of MRI
• Functional Information
• Discussion and Outlook
Swiss Federal Institute of Technology (ETH)• natural and technical sciences • 83 institutes and laboratories, > 11’000 students
University Zurich• all major scientific disciplines (7 faculties)• > 20'000 students
University Hospital Zurich• education site for medical faculty• 130’000 ambulant, 35’000 stationary patients a
year, 960 beds, 5500 employees
Scientific Environment
International Relations• Excellent scientific and industrial relations
Biomechanics Biomedical Electronics
Biomechanics BioelectronicsMedical Optics
P. Niederer R. Müller
D-ITET D-ITET D-MAVT
Biomaterials Tissue Engineering
N.N.
International Zurich Magnetic Resonance Education Center
Biophysics MR Competence CenterMRI / MRS
P. Bösiger
Med. FacultyD-ELEK
MRITechnology
K.P. Prüssmann
D-ELEK
MRI inNeurosci.
N.N.
Med. Fak.
International Zurich Magnetic Resonance Education Center
Institute for Biomedical Engineering
Technical Director: Dieter Meier
Partners at University
• Dept. Radiology:Neuroradiology, Radiology, Nuclear Medicine
• Dept. Internal Medicine:Cardiology , Angiology, Gastroenterology
• Neuroscience:Neurology, Psychiatry, Psychology
Competence Center CCMRI
International Scientific Relations
Inst. for Biomedical EngineeringDivision Biophysics (MRI)
Univ. and ETH ZurichP. Boesiger, K.P. Pruessmann
Johns Hopkins Univ. Baltimore, MD P.van Zijl, X. GolayM. Stuber
Stanford University Stanford, CAC. Bammer
King’s College, London, UKS. Kozerke
German Heart InstituteBerlin, GermanyE. FleckE. Nagel, I. Paetsch
Univ. of CaliforniaSan Francisco, CAC. HigginsO.M. Weber
Harvard Med. School Boston, MAW. ManningR. Botnar
Univ. Hospital AarhusAarhus, Denmark E. Pedersen
Univ. of Minnesota Minneapolis, MN K. UgurbilR. Grütter
Technical Univ. Graz Graz, AustriaK. Perktold
Industrial Relations
Inst. for Biomedical EngineeringDivision Biophysics (MRI)
Univ. and ETH Zurich
Medtronic andBakken ResearchCenter Tolochenaz VD and Maastricht NL
Guerbet Pharmaceuticals Zurich und Paris F
Bracco Imaging Milano I
Roche Pharmaceuticals Basel
Philips Medical Systems Philips Research LaboratoryPhilips Med. Systems Schweiz AGBest NL, Hamburg DE, Zurich CH
Bitplane AGZurich
GyroTools GmbHZurich
ETH and University of Zurich
Philips Medical Systems
University Hospital of Zurich
Project related funding:
SEP; EUREKA / KTI; SNF; Dt. StifterverbandFurther partners from industry and science
Funding
Development of new and dedicated MRI techniques for applications in diagnostics and
therapy as well as in basic medical and clinical research.
Application of these procedures in medical research in collaboration with highly qualified local and international scientific and medical
research groups.
Mission
• MRI Scanner Philips Gyroscan Intera 1.5 Tesla Worldwide fastest MRI commercially available scanner, equipped with parallel imaging technique SENSE
• MRI Scanner Philips Gyroscan Intera 3.0 Tesla Worldwide first 3 T scanner with compact magnet; presently being further developed in collaboration with IBT
Equipment
• High soft tissue contrast
• Contrast adaption
• High spatial resolution
• Arbitrary slice direction
• No known hazards
Advantages of MRI
• Functional information
MRI of the Brain
• anatomy
• angiography
• perfusion, fMRI
• diffusion
• metabolite imaging
Magnetic Resonance Imaging
T2-TSE512 matrix, 2 mm
Sagital Head Images 3Tesla
y
z2D SENSEScan time 26 s
y
z
NONSENSEScan time 106 s
M. Weiger, K. Pruessmann, IBTZ
3D Imaging with 2D SENSE
3D, Inflow MRA
3DI/TONETR 28ms, TE 4.6ms, Flip 20o
scan time 7.30 min100 slices, thickness 1.0/-0.5 matrix 1024
IBTZ, Neuroradiology USZ
High Resolution MRA 3Tesla
High Resolution MRA 3Tesla
Venogram
High Resolution MRA 3Tesla
Arteriovenous Malformation (AVM)
3.0 T1.5 T
Inflow Angiography 1.5 vs. 3.0T
M. Huber, S. Kozerke, IBTZ
NONSENSE R = 2.0 R = 3.0
3D FFE, 3 TeslaTE=3.8ms, TR=19ms
Flip angle=10o
velocity encod = 50cm/s (RL-AP-FH )
slice thickn=0.5 mm120 slices
FOV=190mmmatrix=163x256
SENSE Phase Contrast MRA @ 3T
Decrease of relative concentration of desoxygenated blood, acting as a contrast agent
Increase of T2*, increase of signal amplitude
Activation of brain area:
Raise of metabolic activity
Raise of blood flow
Raise of concentration of oxygenated blood
Brain Activation: BOLD fMRI
Activation of Neurons
Activation of Motor Cortex
C. Schmidt, K. Pruessmann, IBTZ
high-res SENSE sshEPIlow-res conventional sshEPI
stimulation: bilateral opposite finger tapping, 4 x 20s on/off
SENSE: fMRI 3T
Visual Stimulation
4.0
0
A [%]1 2 3
4 5 6
Courtesy: S. Sunaert, Leuven
BOLD fMRI 1.5 vs 3T: Auditory Stimulation
1.5 T
3.0 T
PDw/TSETR 3500 TE 16
T2w/TSETR 3500 TE 110
T1w/IR-TSETR 1400 TE 12 TI 700
T1w/IR-TSETR 1400 TE 12 TI 700
after IV Gd-DOTA
MRI and Perfusion
Direction field mapFractional anisotropy (ordering of fibers)
T. Jaerman, IBTZ, Neurorad USZ
SENSE: Diffusion Tensor Imaging
Diffusion Tensor Imaging
forceps minor
forceps major
external capsule
optic radiation
ant. limb of internal capsule
post. limb of internal capsule(corticospinal tracts)
Characterizing the ORIENTATION of the ellipsoid
Talk T. Jaermann et al, today, 15.00 pm
3T SENSE-DTI: Tracking Results
Functionality:• oblique rotations• introduce new slices• slice shifting• zooming
T. Jaermann, IBTZ, Neurorad USZ Meiyappan Solaiyappan,
Johns Hopkins University
3T SENSE-DTI: White Matter Segmentation
radiation of corpus callosum
volume: 200x200x108mm3
anatomy: 256x256x180SENSE-DWIs: 128x128x36
T. Jaermann, IBTZ, Neurorad USZ
Scan time: 1:04 min, VOI 45 cc
4.0 1.03.0 2.0
Chemical shift (ppm)
NAA
CrCho
MI NAA+Glx
Cr
Glx Lac
Metabolites in 1H MR Spectroscopy
NAA, (P)Cr
NAA: Neuronal marker (neuronal density); concentration correlates with neuronal function
: Tumor, Stroke, Epilepsy, Hyp-/Anoxia, Inflammation, Dementia, Trauma
: Brain Development and Maturation
Cr (PCr): Energy buffer H + PCr + ADP ATP + Cr Energy shuttle: “Energy transport”
The Cr peak is often stable and used as internal reference
: Acute and subacute stroke, brain tumor, brain metastasis, abscesses, inborn errors of Cr synthesis
Choline Containing Compounds = Cho,
Myo-InositolCho: Involved in pathways of phospholipid synthesis
and degradation. => reflecting membrane synthesis and degradation
: Brain Tumors, MS-Plaques, Stroke, Inflammation, White Matter Diseases
: Hepatic Encephalopathy, Necrosis
: Alzheimers’ disease, renal failure, Diabetes mellitus
: Abscesses, Hepatic encephalopathy, tumors, stroke
MI: Astrocyte marker, second messenger
Glutamate and Glutamine = Glx; Lactate
Glutamate: excitatory neurotransmitter, substrate for Krebs-Cycle,Protein Biosynthesis
Glutamine: Substrate for neurotransmitter synthesis (GABA, Glutamate), Protein Biosynthesis
Glx: Stroke, hyp-/anoxia, epilepsy, neurodegenerative diseases, hepatic encephalopathy
Lac: Sign of impaired energy metabolism, impaired oxygen delivery (anaerobic glycolysis).
: Stroke, An-/Hypoxia, mitochondrial diseases, tumors,epileptic discharges, abscesses/infection, prolonged neuronal
activation
Hardly detectable in normal brain tissue (~1 mM)
Single Voxel Spectroscopy @ 3T
TE = 288 ms
VOI = 20 x 20 x 20 mm3
Cerebellum (AMS study)
U. Dydak, IBTZ
NAA
CrCho
Lactate
Mi
before treatment
after treatment
4 3 2 1
NAACr
Cho
Lactate
4 3 2 1
NAACr
Cho
Lactate
Courtesy: Dept. of Radiology, University of Bonn, GermanyCourtesy: Dept. of Radiology, University of Bonn, Germany
Scan time: 4.16 min (35cc)
SVS: tumor treatment
MiMi
Subacute
Acute
Normal
Normal
Courtesy: Tim Roberts, Toronto
FLAIR - ROIs
Cerebral Infarction
Alzheimer’s Disease
The increase () of MI seems to differentiate Alzheimer’s Disease from other forms of dementia
Whole brain TSI
6 slices, 20x20x6 isotropic voxel (1.33ml), = 8.8 Hz
Cho
Cr
NAA
TSI6: Meningioma
NAA
Cho
Single slice, 32 x 32 matrix, TR=2000 ms, 0.8 ml voxel => 5:12 min
U. Dydak, IBTZ
Visualization of 3D MRSI Data
visualization software: IMARIS by Bitplane, Switzerland
NAA maps
3D SENSE-SI
Talk U. Dydak et al, Friday, 10.45 am
SENSE Extremity Imaging @ 3T
3D T1w FFE3.0 TeslaSENSE factor 2150 microns in-plane1mm slice thicknessScantime 8 min.
K.P. Pruessmann, IBTZ D. Weishaupt, Radiology, USZ
Scan time: 4 s / 3D frame
SENSE R=3.0
1.6 × 2.1 × 2.4 mm3
Time-Resolved 3D CE-MRA
SENSE Angiography
M. Weiger, K. Pruessmann, IBTZ
Time-Resolved 3D CE-MRA
ibt / mw kp
4 s / 3D frame1.6 × 2.1 × 2.4 mm3
SENSE R=3.0
SENSE Angiography
Motion Artefact Reduction
Standard Breathhold: 24 sec
SENSE R = 2.0Breathhold: 12 sec
Dep. of Veterans Affairs, Durham
Problem:
• Morphological imaging for many problems insufficient
• Functional diagnostics on a strongly moving organ (heart motion, breathing) at rest and under stress needed.
“One stop shop”.
Cardiovascular MRI
• Coronary artery angiography
• Viability and perfusion
• Wall motion, ejection fraction
• Flow (coronary flow reserve, valvular flow, regurgitation)
Heart functions:
Cardiovascular MRI
Ischemic Cascade
Hypoperfusion
Metabolic changes
Diastolic dysfunction
Regional systolic dysfunction
ECGchanges
Chestpain
Time
spectroscopy
coronary
MRA, flow,
perfusion
motion
viability
Frank H. Netter
Balanced FFE, SENSE R=1.5, 1 breathhold
Courtesy R. Springorum, PMS
MitralValve
TricuspidValve
High Contrast Cardiac Imaging
Chronic Myocardial Injury
S. Flamm, Texas Heart Institute
M. Schaer, S. Kozerke, K.P. Pruessmann, IBTZ
TR = 3.8 ms, Matrix = 213 x 160
Slice = 8 mm, 20 phases
No SENSE15 sec
SENSE 2 x 7 sec
SENSE 3 x 5 sec
Balanced FFE @ 3T
8 k-t SENSE5 coils
8 k-t BLAST1 coil
J. Tsao, K.P. Pruessmann, IBTZ
Real-time SSFP with k-t
No SENSE 9 sec BH, 25 fphb
SENSE R=2 5 sec BH, 25 fphb
SENSE R=2 9 sec BH, 50 fphb
Courtesy M. Kouwenhoven, PMS
fphb = frames per heart beat
Balanced FFE, breathhold
SENSE Cardiac Imaging
ibt
35 ms / frameResol 2.5 mmSENSE R=2.7
Rest Stress 155 bpm
SENSE Real Time Cardiac Imaging
Coronary Arteries
0.75 x 1.0 x 1.5 mm3 0.75 x 1.0 x 0.75 mm3
No SENSE, 20 slices SENSE 2 x, 40 slices
RCA
Coronary Angiography @ 3T
Talk M.E. Huber et al, Friday, 11.30 am
Left coronary arteries;intravascular contrast agent
Right coronary artery;without contrast agent
IBT Zurich / BIDMC Boston / DHZ Berlin / Bracco Milan
Coronary Artery Angiography
• 2D Selective real-time NAV• Free-breathing • VECG• 3D TFE• 600m in-plane resolution• 3mm slice thickness
LAD
Ao
LCX
M. Stuber, BIDMC Boston
Coronary Angiography 3T
IBT Zurich / BIDMC Boston /
A
FED
CB
Coronary Artery Angiography
Myocardial Tagging• 45 heart phases with interval of 13ms• 8mm grid width, 2.8mm x 2.8mm resolution • spiral readout: 12 spirals, acquisition window 5ms
S. Ryf, M. Spiegel, IBTZM. Stuber, BIDMC
Heart Wall Motion
basal level apikal level
Stuber M. et al, Circulation 100, 361, 1999
Heart Wall Motion
anatomy flow
Regurgitation
S. Kozerke, IBTZ
Heart Valve Function : STrack
Heart ValveProsthesis:Particle Tracing
Flow Imaging: STrack
S. Kozerke, IBTZ
Outlook and Discussions
• Higher field strength
• Faster techniques
• Cardiac functions
• Brain organization
And the costs ???
New techniques will be more expensive!BUT:
Modern technique allows for a much better diagnosis!
It is not the medical equipment, which will influence the cost!
The medical staff has to choose the appropriate methods for an
optimal diagnosis and to propose the best therapy or surgery!
• Doctoral StudentsChristof Baltes, el. eng.
Holger Eggers, el. eng.
Michael Huber, el. eng.
Thomas Jaermann, phys.
Thomas Lange, phys.
Roger Luechinger, phys.
Markus Oelhafen, el. eng.
Salome Ryf, phys.
Michael Schär, phys.
Conny Schmidt, phys.
Rolf Schulte, phys.
Andreas Steingoetter, el. eng
Reto Treier, phys.
Florian Wiesinger, phys.
• ChairmenPeter Boesiger, PhD
Klaas Pruessmann, PhD
• Research AssistantsUlrike Dydak, PhD
Roger Luechinger, PhD
Jeff Tsao, PhD
Andreas Trabesinger, PhD
Gérard Crelier, PhD
• Project LeadersDieter Meier, PhD
Sebastian Kozerke, PhD
Markus Scheidegger, PhD
Present Team