MRI at a Glance

Preface vii Acknowledgements viii How to use your textbook ix About the companion website xi 1 Magnetism and electromagnetism 2 2 Atomic structure 4 3 Alignment 6 4 Precession 8 5 Resonance and signal generation 10 6 Contrast mechanisms 12 7 Relaxation mechanisms 14 8 T1 Recovery 16 9 T2 decay 18 10 T1 weighting 20 11 T2 weighting 22 12 PD weighting 24 13 Conventional spin echo 26 14 Fast or turbo spin echo – how it works 28 15 Fast or turbo spin echo – how it is used 30 16 Inversion recovery 32 17 Gradient echo – how it works 34 18 Gradient echo – how it is used 36 19 The steady state 38 20 Coherent gradient echo 40 21 Incoherent gradient echo 42 22 Steady-state free precession 44 23 Balanced gradient echo 46 24 Ultrafast sequences 48 25 Diffusion and perfusion imaging 50 26 Functional imaging techniques 52 27 Gradient functions 54 28 Slice selection 56 29 Phase encoding 58 30 Frequency encoding 60 31 K space – what is it? 62 32 K space – how is it filled? 64 33 K space and image quality 66 34 Data acquisition – frequency 68 35 Data acquisition – phase 70 36 Data acquisition – scan time 72 37 K space traversal and pulse sequences 74 38 Alternative K space filling techniques 76 39 Signal to noise ratio 78 40 Contrast to noise ratio 80 41 Spatial resolution 82 42 Chemical shift artefacts 84 43 Phase mismapping 86 44 Aliasing 88 45 Other artefacts 90 46 Flow phenomena 92 47 Time-of-flight MR angiography 94 48 Phase contrast MR angiography 96 49 Contrast-enhanced MR angiography 98 50 Contrast agents 100 51 Magnets 102 52 Radiofrequency coils 104 53 Gradients and other hardware 106 54 MR safety – bio-effects 108 55 MR safety – projectiles 110 Appendix 1a: The results of optimizing image quality 112 Appendix 1b: Parameters and their associated trade-offs 113 Appendix 2: Artefacts and their remedies 114 Appendix 3: Main manufacturers’ acronyms 115 Glossary 116 Index 121