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Cho. Cre. Cit. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY. Basic MRI principles. Yves De Deene. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY. NMR. N uclear M agnetic R esonance. MRR. MRS. MRI. M agnetic R esonance S pectroscopy. M agnetic R esonance

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  1. Cho Cre Cit RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Basic MRI principles Yves De Deene

  2. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY NMR Nuclear Magnetic Resonance MRR MRS MRI Magnetic Resonance Spectroscopy Magnetic Resonance Imaging Magnetic Resonance Relaxometry Spatial Tissue Differentiation Molecular Composition Molecular Dynamics Basic MRI principles  Yves De Deene

  3. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY MRR MRS MRI Magnetic Resonance Spectroscopy Magnetic Resonance Imaging Magnetic Resonance Relaxometry Relaxation times, Diffusion coefficients Images Spectra Basic MRI principles  Yves De Deene

  4. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY NMR imaging is non-invasive Strong static magnetic field Radiofrequent electromagnetic waves Space and time dependent magnetic fields Basic MRI principles  Yves De Deene

  5. mp = 0,00000000000000000000000167 g mp = 1,67.10-24 g qp = 0,00000000000000000016 C + + + + + + + + + qp = 1,6.10-19 C + RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Properties of the atomic nucleus Water H2O Basic MRI principles  Yves De Deene

  6. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Discovery of nuclear magnetic resonance 1938 Off resonance N N N In resonance Z Isidor Isaac Rabi Z Z Spin reservoir oven Molecular beam apparatus Basic MRI principles  Yves De Deene

  7. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Nuclear magnetic resonance in a block of parafin 1946 N Block of parafin IDC B Electromagnetic wave with fixed frequency f S Edward Purcell -1/2 E Absorption +1/2 IDC ~ B B Nobel price physics (Bloch & Purcell) in 1952 Basic MRI principles  Yves De Deene

  8. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Nuclear magnetic resonance mathematical description The Bloch equations 1946 Felix Bloch Basic MRI principles  Yves De Deene

  9. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Precession in a magnetic field Basic MRI principles  Yves De Deene

  10. COIL Water molecule RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY MRI signal generation B0 B0 B0 Cryogenic magnet Hydrogen proton transmits a radiofrequent electromagnetic wave (yellow) after excitation by an RF pulse (red) EXCITATION PULSE Gradient coils Radiofrequency transmit/receive coil Image Processing (2D-FFT) Basic MRI principles  Yves De Deene

  11. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY MRI signal excitation / reception Signal reception Excitation OBJECT: Spin system OBJECT: Spin system COIL COIL Basic MRI principles  Yves De Deene

  12. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY The first MRI scanner 1972 2p.f= g. B Resonance condition fulfilled Raymond V. Damadien Raymond V. Damadien Inhomogeneous magnetic field First MRI scan Basic MRI principles  Yves De Deene

  13. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Current MR scanners Interventional MR unit Clinical MR scanner Animal MR scanner Open MR unit Mobile MR unit Basic MRI principles  Yves De Deene

  14. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY MRI signal generation Yes, but... what about spatial encoding ?? ? Wave length  (m) MRI X-ray CT Photon energy E (eV) Gamma -rays radiofrequency Tera- hertz IR UV micro- wave X-rays visible HF MF VLF VHF LF SHF SLF ULF UHF EHF ELF Frequency f (Hz) inner electrons nuclear Interaction with matter inner & outer electrons nuclear spin electron spin outer electrons molecular vibrations and rotations Basic MRI principles  Yves De Deene

  15. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY MRI encoding An analogon in acoustics 1 2 3 Basic MRI principles  Yves De Deene

  16. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY MRI encoding: slice selection An analogon in acoustics 1 2 3 Basic MRI principles  Yves De Deene

  17. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY MRI encoding: Slice selection X-gradient B y-coil z z-coil x-coil Y-gradient GRADIENT COILS patient 1.52 T Z-gradient f = 64.8 MHz 64.8 MHz Basic MRI principles  Yves De Deene

  18. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY MRI frequency encoding An analogon in acoustics 1 2 3 Basic MRI principles  Yves De Deene Frequency encoding

  19. RF COIL Fourier transform RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY MRI frequency encoding Basic MRI principles  Yves De Deene

  20. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY 2D spatial encoding Richard Ernst Basic MRI principles  Yves De Deene

  21. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Dephasing – T2* decay In free space In human tissue IN PHASE OUT OF PHASE Basic MRI principles  Yves De Deene

  22. N TURN BACK !! Z RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY The spin-echo sequence 1949 EXCITATION PULSE (90°) REFOCUSSING PULSE (180°) REFOCUSSING PULSE (180°) EXCITATION PULSE (90°) TE/2 TE/2 Basic MRI principles  Yves De Deene

  23. (90°) SLICE SELECTION B z 1.52 T f = 64.8 MHz 1.52 T RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY The spin-echo sequence Slice selection Basic MRI principles  Yves De Deene

  24. (90°) PHASE ENCODING y B RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY The spin-echo sequence Phase encoding Basic MRI principles  Yves De Deene

  25. (90°) FREQUENCY ENCODING B y T 1.43 1.53 1.5 RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY The spin-echo sequence Frequency encoding (180°) Basic MRI principles  Yves De Deene

  26. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY The spin-echo sequence 180° PULSE 180° PULS 90° PULSE 90° PULSE TE/2 TE/2 TE/2 TE/2 GSL GRO GPH Basic MRI principles  Yves De Deene

  27. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY The spin-echo sequence fc+Df fc fc 180° PULSE 180° PULSE slice I 90° PULSE 90° PULSE TE/2 TE/2 TE/2 TE/2 GSL 180° PULSE slice II 90° PULSE TE/2 TE/2 GSL Basic MRI principles  Yves De Deene

  28. FREQUENCY AND PHASE ENCODING 2D-FOURIER TRANSFORM AMPLITUDE IMAGE RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY The spin-echo sequence SLICE SELECTION z (f , f) PHASE (f) FREQUENCY (f) Basic MRI principles  Yves De Deene

  29. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY K-space with For 3D imaging (ignoring relaxation) For 2D imaging (z = z0) (x,y,z=z0) S(kx,ky) 2D FFT Basic MRI principles  Yves De Deene

  30. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY K-space Phase Encoding Gradient Spin-echo with Basic MRI principles  Yves De Deene

  31. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Image space k-space K-space IMAGINARY REAL IMAGINARY REAL FFT MAGNITUDE PHASE MAGNITUDE PHASE Basic MRI principles  Yves De Deene

  32. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Walking through K-space The spin echo sequence ky 180° PULS 90° PULSE TE/2 TE/2 E kx A D GSL = Gz B C GRO = Gx GPH = Gy B C D A E Basic MRI principles  Yves De Deene

  33. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Walking through K-space The spin echo sequence ky 180° PULS 90° PULSE TE/2 TE/2 E kx A D GSL = Gz B C GRO = Gx GPH = Gy Imaging time = TR. NEX.Nphase B C D A E Basic MRI principles  Yves De Deene

  34. RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Spin-lattice and spin-spin decay Dipolar interaction Spin-lattice decay T1 Spin-spin decay T2 Longitudinal relaxation Transverse relaxation B0 B0 time time Basic MRI principles  Yves De Deene

  35. M t M t M C t RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Spin-spin decay and molecular dynamics Hydrogen bridges FREE WATER High mobility INTERMEDIATE LAYER + + + - + + - O + - + - O - + - C BOUND LAYER + N C + + + - Low mobility Protein, polymer, cell membrane Basic MRI principles  Yves De Deene

  36. Anatomical imaging: Multiple sclerosis RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Anatomical imaging: Multiple sclerosis Proton density (transverse) T2 weighted (transverse) T1 weighted With contrastagent Proton density (sagital) Cluster analysis (T1w, T2w, PDw) Basic MRI principles  Yves De Deene

  37. Anatomical Imaging: Arterio venous diseases RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Arterio venous diseases Arterio venous malformation (AVM) Aneurism T2 weighted (transverse) MR angiography MR angiography MR angiography Thrombosis Infarct (‘stroke’) Neck trauma MR angiography Proton density Proton density T2 weighted T2 weighted Basic MRI principles  Yves De Deene

  38. Anatomical imaging: Oncology RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Oncology T2 weighted (cyst) T1 weighted with contrastagent (Breast carcinoma) Protondensity (Brain metastasis) T2 weighted (chondrosarcoma) T2 weighted (cervix carcinoma) T2 weighted (prostate tumor) Basic MRI principles  Yves De Deene

  39. Anatomical imaging Bone and soft tissue RESEARCH GROUP QUANTITATIVE MRI IN MEDICINE AND BIOLOGY Bone and soft tissue rheumatoid arthritis knee rheumatoid arthritis whrist T2 weighted (torn ligaments) T2 weighted (hernia) Osteoporosis (femur) Basic MRI principles  Yves De Deene

  40. I visited Copenhagen frequently after the war. At one point, I gave a talk in Copenhagen, and then afterwards we met with Bjerrum. Bjerrum was a chemist and a great friend of Niels Bohr… Bohr said to him: “You know, what these people do is really very clever. They put little spies into the molecules and send radio signals to them, and they have to radio back what they are seeing.” I thought that was a very nice way of formulating it. That was exactly how they were used. It was not anymore the protons as such. But from the way they reacted, you wanted to know in what kind of environment they are, just like spies that you send out. That was a nice formulation. - Felix Bloch -

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