Foreword ....................................................... ix
Guy Frija
Chapter 1. Ultrasound Medical Imaging ........................... 1
Didier Vray, Elisabeth Brusseau, Valérie Detti, Francois
Varray, Adrian Basarab, Olivier Beuf, Olivier Basset,
Christian Cachard, Hervé Liebgott, Philippe Delachartre
1.1 Introduction ............................................... 1
1.2 Physical principles of echography .......................... 3
1.2.1 Ultrasound waves .................................... 3
1.2.2 Wavefronts .......................................... 4
1.2.3 Stress/Strain relation .............................. 5
1.2.4 Propagation equation ................................ 6
1.2.5 Acoustic impedance .................................. 7
1.2.6 Acoustic intensity .................................. 7
1.2.7 Mechanical Index .................................... 9
1.2.8 Generation, emission ................................ 9
1.2.9 Resolution ......................................... 10
1.2.10 Propagation of a plane wave in a finite isotropic
medium ............................................. 11
1.2.11 Propagation of a plane wave in a non-homogeneous
medium ............................................. 13
1.2.12 Speckle ............................................ 15
1.2.13 Nonlinear waves .................................... 16
1.2.14 Contrast agents .................................... 17
1.3 Medical ultrasound systems ................................ 18
1.3.1 Principle .......................................... 18
1.3.2 The different stages in image formation ............ 19
1.3.3 Ultrasound imaging probe ........................... 21
1.3.4 Modes of imaging, B-mode and M-mode, and harmonic
imaging modes ...................................... 24
1.3.5 Doppler imaging .................................... 27
1.4 The US image .............................................. 34
1.4.1 Properties of speckle, echostracture and
statistical laws ................................... 34
1.4.2 Segmentation of US images .......................... 38
1.4.3 Simulation of US images ............................ 41
1.5 Recent advances in ultrasound imaging ..................... 44
1.5.1 Generation/emission of ultrasounds ................. 44
1.5.2 Signal-and image processing ........................ 49
1.5.3 Multimodal imaging ................................. 60
1.6 A bright future for ultrasound imaging .................... 65
1.7 Bibliography .............................................. 65
Chapter 2. Magnetic Resonance Imaging .......................... 73
Dominique Sappey-Marinier and André Briguet
2.1 Introduction .............................................. 73
2.2 Fundamental elements for MRI .............................. 76
2.2.1 Introduction ....................................... 76
2.2.2 Vectorial description of nuclear magnetic
resonance (NMR) .................................... 78
2.2.3 RF pulses and their effect on magnetizations ....... 88
2.2.4 Elementary pulse sequences using the refocusing
technique .......................................... 97
2.2.5 Spatial discrimination of signals using
gradients: fundamental principle of MRI ........... 106
2.2.6 Multi-parameter aspect of MRI ..................... 110
2.3 Instrumentation .......................................... 115
2.3.1 Introduction ...................................... 115
2.3.2 Recording the signal .............................. 117
2.3.3 Magnetic systems .................................. 129
2.3.4 A typical MRI installation in a clinical
environment ....................................... 136
2.3.5 Operation and safety .............................. 139
2.4 Image properties ......................................... 144
2.4.1 Introduction ...................................... 144
2.4.2 Field of view ..................................... 144
2.4.3 Spatial resolution ................................ 148
2.4.4 Contrast and signal ............................... 155
2.4.5 Contrast elements in MRI practice ................. 162
2.5 Imaging sequences and modes of reconstruction ............ 168
2.5.1 Introduction ...................................... 168
2.5.2 Overall view of acquisition sequences ............. 168
2.5.3 Modes of reconstruction ........................... 195
2.6 Application of MRI: uses and evolution in the
biomedical field ......................................... 208
2.6.1 Introduction ...................................... 208
2.6.2 Spectroscopy and imaging: technical and clinical
complementarity ................................... 210
2.6.3 Diffusion MRI: a morphological and functional
approach .......................................... 217
2.6.4 Functional MRI (fMRI) of cerebral activation ...... 236
2.6.5 Bi-modal approach to MRI: the example of MR/PET ... 239
2.7 Bibliography ............................................. 244
List of Authors .......................................... 263
Index ......................................................... 265
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