1 Introduction ................................................. 1
2 Breast diagnostics ........................................... 7
2.1 Introduction ............................................ 7
2.2 The female breast ....................................... 8
2.2.1 Anatomy .......................................... 8
2.3 Breast lesions .......................................... 9
2.3.1 Benign variations ................................ 9
2.3.2 Malignant varations ............................. 10
2.4 Therapy and treatment of lesions ....................... 10
2.4.1 Surgery ......................................... 11
2.4.2 Medication ...................................... 11
2.4.3 Radiation ....................................... 11
2.5 Breast imaging ......................................... 11
2.5.1 X-ray mammography ............................... 12
2.5.2 Sonography ...................................... 13
2.5.3 Magnetic resonance imaging ...................... 13
2.5.4 Sensitivity and specificity of modalities ....... 13
2.6 Perspectives ........................................... 14
3 Breast magnetic resonance imaging ........................... 17
3.1 Magnetic resonance imaging ............................. 17
3.1.1 Principles ...................................... 17
3.1.2 MR imaging ...................................... 18
3.2 Breast MRI ............................................. 19
3.2.1 Morphologic breast MRI .......................... 19
3.2.2 DCE breast MRI .................................. 20
3.2.3 Enhancement characteristics ..................... 21
3.2.4 Diagnostic protocols and software ............... 21
3.3 Breast MRI perturbations ............................... 23
3.3.1 Intrinsic factors ............................... 23
3.3.2 Extrinsic factors ............................... 24
3.4 Image registration for breast MRI ...................... 27
3.4.1 Motion correction ............................... 28
3.4.2 Inter-sequence alignment ........................ 28
3.4.3 Current/prior synchronization ................... 29
3.4.4 Algorithm requirements .......................... 30
3.5 Perspectives ........................................... 30
4 Intensity-based image registration .......................... 33
4.1 Principles ............................................. 33
4.1.1 Paradigm ........................................ 35
4.1.2 Registration components ......................... 35
4.2 Generic registration framework ......................... 53
4.2.1 Object-oriented framework layout ................ 54
4.2.2 Iterative registration paradigm ................. 55
4.2.3 Interactive extension interface ................. 56
4.2.4 Standard image registration ..................... 58
4.2.5 Initialization and macro modules ................ 59
4.2.6 Visualizing the registration result ............. 60
4.2.7 Performance optimization ........................ 60
4.2.8 Comparison to other registration frameworks ..... 61
4.2.9 Applications .................................... 64
4.2.10 Rapid registration prototyping using MERIT ...... 67
4.2.11 Availability .................................... 68
4.3 Perspectives ........................................... 68
5 Non-linear image registration ............................... 69
5.1 Introduction ........................................... 69
5.1.1 Parametric non-linear image registration ........ 69
5.1.2 Non-parametric non-linear image registration .... 71
5.2 Non-linear registration ................................ 72
5.2.1 Non-linear registration scheme .................. 72
5.2.2 Non-linear image transformations ................ 73
5.2.3 Image similarity ................................ 74
5.2.4 Regularization .................................. 75
5.2.5 Deformation update rules ........................ 78
5.2.6 Boundary conditions ............................. 79
5.2.7 Non-linear algorithm ............................ 83
5.3 Implementation ......................................... 84
5.3.1 MERIT plugins ................................... 85
5.3.2 Hardware acceleration ........................... 85
5.4 Extensions ............................................. 88
5.4.1 Volume-preservation ............................. 89
5.4.2 Inverse consistency ............................. 92
5.5 Practical deformable registration ..................... 100
5.5.1 Limitations and benefits of non-linear
registration methods ........................... 100
5.5.2 Application of volume-preservation ............. 100
5.5.3 Application of inverse-consistency ............. 100
5.6 Perspectives .......................................... 101
6 Validation of breast MRI registration ...................... 103
6.1 Introduction .......................................... 103
6.1.1 Challenges for the evaluation of breast MRI
registration ................................... 104
6.1.2 Evaluation requirements ........................ 106
6.1.3 Qualitative evaluation ......................... 107
6.1.4 Quantitative evaluation ........................ 114
6.1.5 Hardware phantoms .............................. 121
6.1.6 Practical evaluation ........................... 123
6.2 Bio-mechanical breast models .......................... 124
6.2.1 Introduction ................................... 124
6.2.2 State-of-the-art in breast modeling ............ 125
6.2.3 Newton's laws .................................. 127
6.2.4 Mesh geometries ................................ 128
6.2.5 Mass-spring model .............................. 129
6.2.6 Linear-elastic finite-element model ............ 133
6.2.7 Stress and strain .............................. 134
6.2.8 Constituent equations .......................... 135
6.2.9 Energy formulation ............................. 138
6.2.10 Finite-element discretization .................. 138
6.2.11 Simulation scheme .............................. 143
6.2.12 Contact mechanics .............................. 144
6.2.13 Practical modeling ............................. 150
6.2.14 Summary of validation methods .................. 150
6.3 An indicator for motion correction quality ............ 151
6.3.1 Temporal maximum-intensity projections ......... 152
6.3.2 Multi-scale Hessian analysis ................... 153
6.3.3 Analyzing the deformation ...................... 155
6.4 Generation of breast models ........................... 161
6.4.1 Synthetic breast shapes ........................ 161
6.4.2 Image-based breast shapes ...................... 162
6.5 Perspectives .......................................... 167
7 Breast MRI applications .................................... 169
7.1 Motion correction ..................................... 169
7.1.1 State-of-the-art ............................... 169
7.1.2 Clinical requirements .......................... 172
7.1.3 Methods ........................................ 174
7.1.4 Results ........................................ 175
7.1.5 Discussion ..................................... 201
7.2 Alignment of T2- and T1-weighted breast MR images ..... 202
7.2.1 State-of-the-art ............................... 203
7.2.2 Methods ........................................ 204
7.2.3 Results ........................................ 207
7.2.4 Discussion ..................................... 211
7.3 Synchronization of current/prior breast MR images ..... 212
7.3.1 State-of-the-art ............................... 213
7.3.2 Methods ........................................ 213
7.3.3 Results ........................................ 217
7.3.4 Discussion ..................................... 223
7.4 Perspectives .......................................... 224
8 Discussion ................................................. 225
8.1 Summary ............................................... 225
8.2 Outlook ............................................... 226
References .................................................... 231
List of Figures ............................................... 247
| 
