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