Breast MRI (eBook)

Dr. Edward Hendrick, Ph.D., FACR, has played a pivotal role in improving the quality of mammorgraphy worldwide as well as making important contributions to magnetic resonance (MR) imaging.  His groundbreaking work with the American College of Radiology (ACR) helped establish the ACR Mammography Accreditation Program, which lead to the Mammography Quality Standards Act of 1992 - legislation enaced to ensure mammography facilities offer patients the best medical technology and care.  He is recognized as a national leader in advancing breast imaging and cancer detection techniques.

Foreword 6
Preface 8
Contents 10
Fundamentals of Magnetic Resonance Imaging 16
Subatomic Particles 18
The Atom 19
Magnetic Dipole Moments 21
Nuclear Magnetic Moments 24
Tissue Magnetization 25
Magnetic Fields 28
Precession and Magnetic Resonance 29
Tissue Excitation 29
Measuring the Magnetic Resonance Signal 30
The Basic Nuclear Magnetic Resonance Experiment 31
Chapter Take-home Points 31
References 32
Tissue Relaxation 33
Nuclear Magnetic Resonance 33
T1 Relaxation 35
T2 Relaxation 37
Distinguishing T2 and T2* 39
The Physical Basis of Relaxation Times 42
Chapter Take-home Points 43
References 43
Spatial Resolution in Magnetic Resonance Imaging 44
Basic Components of a Magnetic Resonance Imaging System 44
Slice Selection in Magnetic Resonance Imaging 49
Magnetic Resonance Imaging Pulse Sequence 51
Forming a Magnetic Resonance Image 54
Chapter Take-home Points 57
References 58
The Spin-echo Pulse Sequence 59
Spin-echo Pulse Sequence Diagram 59
Signal Dependence on TR and TE in Spin-echo Imaging 63
Contrast in Spin-echo Imaging 65
Acquisition Times in Spin-echo Imaging 68
Multi-slice Imaging 68
Chapter Take-home Points 70
References 70
Gradient Echo Sequences and 3D Imaging 71
The Gradient-echo Pulse Sequence Diagram 72
Variants of Gradient-echo Imaging 75
Signal Dependence on TR, TE, and q in Spoiled Gradient-echo Imaging 76
Contrast in Spoiled Gradient-echo Pulse Sequences 78
Steady-state Gradient-echo Imaging 79
Total Acquisition Time in 2D Gradient-echo Imaging 80
3D Gradient-echo Imaging 81
Chapter Take-home Points 84
References 85
Suggested Reading 85
Fast-spin Echo, Echo Planar, Inversion Recovery, and Short- T1 Inversion Recovery Imaging 86
Fast Spin-echo Imaging 86
Echo-planar Imaging 91
Inversion Recovery and Short-T1 Inversion Recovery Imaging 94
Chapter Take-home Points 100
References 102
Signal, Noise, Signal-to-Noise, and Contrast- to- Noise Ratios 103
Magnetic Resonance Signal 103
Noise in a Magnetic Resonance Image 104
System Parameters Affecting Noise 109
Signal-to-Noise Ratios 110
Effect of User-selectable Image Acquisition Parameters on Signal- to- Noise Ratios 112
Putting Together All Factors Affecting Signal-to-Noise Ratios 115
Contrast and Contrast-to-Noise Ratios 117
The Rose Model 118
Effect of Image Addition on Signal, Noise, Signal-to-Noise Ratios and Contrast- to- Noise Ratios 119
Effect of Image Subtraction on Signal, Noise, Signal-to-Noise Ratios and Contrast- to- Noise Ratios 120
Chapter Take-home Points 121
References 121
Contrast Agents in Breast Magnetic Resonance Imaging 122
A Brief History of Contrast Media in the Breast 122
Gadolinium-based Contrast Agents 122
The Physiologic Basis of Contrast Enhancement 127
Dosage of Gadolinium-chelated Contrast Agents 129
Safety of Gadolinium-chelated Contrast Agents 129
Sensitivity and Specificity of Contrast-enhanced Breast Magnetic Resonance Imaging 132
Trade-offs Between Adequate Temporal Resolution and Adequate Spatial Resolution 138
Obtaining High Temporal Resolution and High Spatial Resolution Contrast- enhanced Studies 139
Enhancement of Normal Fibroglandular Tissues in Pre- menopausal Women 139
Chapter Take-home Points 140
References 141
Suggested Reading 143
Breast Magnetic Resonance Imaging Acquisition Protocols 144
Essential Elements of an Image Acquisition Protocol 144
Magnetic Field Strength of at Least 1.5 T and High Magnetic Field Homogeneity 151
Bilateral Imaging with Prone Positioning 151
3D Gradient-echo T1-weighted Pulse Sequences for Contrast- enhanced Imaging 153
Good Fat Suppression over Both Breasts in Contrast-enhanced Breast Magnetic Resonance Imaging 154
Adequately Thin Image Slices 154
Pixel Sizes of Less than 1 mm in Each in-plane Direction 155
Proper Selection of the Phase-encoding Direction to Minimize Artifacts Across the Breasts 156
A Total 3D Fourier Transform Acquisition Time for Both Breasts of Less than 2 Minutes 158
Meeting Temporal and Spatial Resolution Requirements in 3D Gradient- echo Imaging 159
Optimizing Contrast-enhanced Studies 170
Examples of Contrast-enhanced Scanning Protocols Meeting Temporal and Spatial Requirements 171
Examples of Deficient Contrast-enhanced Protocols 172
Chapter Take-home Points 177
References 177
Image Post-processing Protocols 179
Automated or Prescribed Post-processing Techniques 179
Breast Magnetic Resonance Imaging Computer-aided Diagnosis Workstations 192
Chapter Take-home Points 193
References 193
Artifacts and Errors in Breast Magnetic Resonance Imaging 195
Artifacts 195
Other Equipment and User Errors 210
Chapter Take-home Points 214
References 215
Magnetic Resonance Imaging Safety and Patient Considerations 216
Static Magnetic Fields 217
Gradient Magnetic Fields 221
Radiofrequency Fields 222
Other Patient and Personnel Safety Considerations Patients, Visitors, or Site Personnel with Metallic Implants and Devices 223
Chapter Take-home Points 226
References 226
New Developments in Breast Magnetic Resonance Imaging 228
Higher Field Systems 228
Dedicated Breast Magnetic Resonance Imaging Systems 230
Dedicated Breast Magnetic Resonance Imaging Table and Coils 231
Novel Techniques to Improve the Specificity of Breast Magnetic Resonance Imaging 232
Conclusion 239
Chapter Take-home Points 241
References 241
Appendix: Magnetic Resonance Imaging Patient and Non- Patient Screening Forms 244
Index 249