Table of Contents
Editor’s Preface xiii
Series Editor’s Preface xv
1 Magnets for Small-Scale and Portable NMR 1
Bernhard Blümich, Christian Rehorn, and Wasif Zia
1.1 Introduction 1
1.2 Compact Permanent Magnets 3
1.2.1 Types of Permanent Magnets 3
1.2.2 Stray-Field Magnets 5
1.2.2.1 Classification 5
1.2.2.2 Magnets for 1D and 2D Imaging 6
1.2.2.3 Magnets for Bulk-Volume Analysis 7
1.2.3 Center-Field Magnets 9
1.3 Magnet Development 10
1.3.1 PermanentMagnet Materials 10
1.3.2 Magnet Construction and Passive Shimming 11
1.3.3 Overview of Center-field Magnets for Compact NMR 11
1.3.4 Strategies for Passive Shimming 13
1.3.5 Shim Coils for Compact NMR Magnets 14
1.4 Concluding Remarks 16
References 16
2 Compact Modeling Techniques for Magnetic Resonance Detectors 21
Suleman Shakil,Mikhail Kudryavtsev, Tamara Bechtold, Andreas Greiner,mand Jan G. Korvink
2.1 Introduction 21
2.2 Fast Simulation of EPR Resonators Based on Model OrdermReduction 22
2.2.1 The Discretized Maxwell’s Equations 23
2.2.2 Model Order Reduction 29
2.2.3 Structure-PreservingModel Order Reduction 33
2.2.4 Planar Coil EPR Resonator 34
2.3 System Level Simulation of a Magnetic Resonance Microsensor bymMeans of ParametricModel Order Reduction 39
2.3.1 Model Description 40
2.3.2 ParametricModel Order Reduction 43
2.3.3 Compact Model Simulation Results 46
2.3.4 Device–Circuit Co-simulation 46
2.4 Conclusions and Outlook 54
References 55
3 Microarrays andMicroelectronics for Magnetic Resonance 59
Oliver Gruschke, Mazin Jouda, and Jan G. Korvink
3.1 Introduction 59
3.2 Microarrays for Magnetic Resonance 59
3.2.1 Theoretical Background 59
3.2.2 Microtechnologies for MR Array Fabrication 61
3.3 Integrated Circuits 63
3.4 CMOS Frequency Division Multiplexer 64
3.4.1 The Low-Noise Amplifier 64
3.4.2 The Frequency Mixer 65
3.4.3 The Bandpass Filter 66
3.4.4 Measurements 67
3.4.4.1 MRI Experiment 68
3.5 Summary 70
References 70
4 Wave Guides for Micromagnetic Resonance 75
Ali Yilmaz andMarcel Utz
4.1 Introduction 75
4.2 Wave Guides: Theoretical Basics 78
4.2.1 Propagating Electromagnetic Modes 78
4.2.2 Characteristic Impedance and Transport Characteristics 79
4.2.3 Theory of TEMWave Modes 79
4.2.4 Modeling of TEM Modes 80
4.2.4.1 Losses in Transmission Lines 82
4.2.5 Magnetic Fields in Planar TEM Transmission Lines 82
4.2.6 Transmission Line Detectors and Resonators 83
4.3 Designs and Applications 84
4.3.1 Microstrip NMR Probes in MRI 84
4.3.2 Microfluidic NMR 87
4.3.3 Planar Detectors 87
4.3.4 Microstrip Detectors 88
4.3.5 Nonresonant Detectors 90
4.3.6 Stripline Detectors 92
4.3.7 Parallel Plate Transmission Lines 96
4.3.8 Applications in Solid-State Physics 97
4.3.9 Wave Guides for Dynamic Nuclear Polarization 98
References 100
5 Innovative Coil Fabrication Techniques for Miniaturized Magnetic Resonance Detectors 109
Jan Korvink, Vlad Badilita, DarioMager, Oliver Gruschke, Nils Spengler, Shyam Sundar Adhikari Parenky, UlrikeWallrabe, andMarkusMeissner
5.1 Wire-Bonding – A New Means to Miniaturize MR Detectors 109
5.2 Microcoil Inserts for Magic Angle Spinning 114
5.2.1 Backbone of the Magic Angle Coil Spinning (MACS) Technique 115
5.2.2 Cost of Inductive Coupling 116
5.2.3 Demonstrating the Improved Sensitivity of the MACS Technique from NMR Experiments 118
5.2.4 Microfabricated MACS Inserts 118
5.2.5 Double-Resonant MACS Insert 120
5.3 Micro-Helmholtz Coil Pairs 123
5.3.1 Helmholtz Coils in Magnetic Resonance 123
5.3.2 Magnetic Field Profile 124
5.3.3 Micromachining of Miniaturized Helmholtz Pairs 125
5.4 High Filling Factor Microcoils 128
5.4.1 Introduction 128
5.4.2 Fabrication 130
5.4.3 Results 130
5.5 Coil Fabrication Using Inks 130
References 136
6 IC-Based and IC-Assisted ;;NMR Detectors 143
Jonas Handwerker and Jens Anders
6.1 Technological Considerations and Device Models 143
6.1.1 ComplementaryMetal Oxide Semiconductor Technologies 143
6.1.2 Bipolar ComplementaryMetal Oxide Semiconductor Technologies 148
6.2 Monolithic Transceiver Electronics for NMR Applications 151
6.2.1 Optimal Integrated RF Front-ends for μNMR Applications 151
6.2.2 Designing NMR Receivers in CMOS and BiCMOS 155
6.2.2.1 LNAs forWidebandand Applications 156
6.2.2.2 LNAs for Narrowband Applications 163
6.2.3 Co-design of the Detection Coil and the LNA for SNR Optimization 167
6.3 Overview of the State-of-the-Art in IC-Based and IC-Assisted μNMR 167
6.3.1 Portable NMR Systems 167
6.3.2 NMR Spectroscopy Systems 170
6.3.3 MR Imaging and Microscopy Systems 171
6.3.4 Intravascular NMR Systems 173
6.4 Summary and Conclusion 174
References 174
7 MR Imaging of Flow on theMicroscale 179
Dieter Suter and Daniel Edelhoff
7.1 Introduction 179
7.2 Methods – Flow Imaging 179
7.2.1 Time of Flight 180
7.2.2 Phase Contrast 181
7.2.3 Mean Flow 182
7.2.4 Limitations 182
7.2.4.1 Velocity Range 183
7.2.4.2 Temporal Stability 184
7.2.4.3 Spatial Resolution 184
7.3 Applications of Microscopic Flow Imaging 185
7.3.1 Experimental Setup 186
7.3.2 Characterization of Liquid Exchange in Aneurysm Models 186
7.3.2.1 AneurysmModels 186
7.3.2.2 Methods 186
7.3.2.3 Results 187
7.3.2.4 Conclusion 189
7.3.3 Phase–Contrast Measurements with Constant Flow 189
7.3.3.1 Laminar Flow in a Pipe 189
7.3.3.2 Flow andWall Shear Stress in an Aneurysm Model 190
7.3.4 Pulsatile Flow 192
7.4 Discussion 194
Acknowledgments 195
References 195
8 Efficient Pulse Sequences for NMRMicroscopy 199
Jürgen Hennig, Katharina Göbel-Guéniot, Linnéa Hesse, and Jochen Leupold
8.1 Introduction 199
8.2 Spatial Encoding 200
8.2.1 k-Space and More 200
8.2.2 Slice Selection 204
8.3 Contrast Mechanisms 206
8.3.1 T1-relaxation 206
8.3.2 T2-relaxation 207
8.3.3 T2*-decay 207
8.4 Basic Pulse Sequences 211
8.4.1 General Considerations 211
8.4.2 Spin Echo Sequences 212
8.4.3 Gradient Echo-Based Imaging 214
8.4.3.1 FLASH-Type Gradient Echoes 214
8.4.3.2 EPI 219
8.4.4 Ultrashort TE 220
8.5 Special Contrasts 222
8.5.1 Diffusion 222
8.5.1.1 Diffusion Limit of NMR Microscopy 224
8.5.2 Flow 229
8.5.2.1 Velocity Phase Imaging 229
8.5.2.2 Time-of-Flight Imaging 230
8.5.3 Susceptibility Mapping and QSM 230
References 232
9 Thin-Film Catheter-Based Receivers for Internal MRI 237
Richard R. A. Syms, Evdokia Kardoulaki, and Ian R. Young
9.1 Introduction 237
9.2 Catheter Receivers 237
9.2.1 Internal Imaging 238
9.2.2 Catheter Receiver Designs 238
9.2.3 Elongated Loop Receivers 239
9.2.4 Tuning and Matching 240
9.2.5 B1-Field Decoupling 241
9.2.6 E-Field Decoupling 242
9.3 Thin-Film Catheter Receivers 244
9.3.1 Thin-Film Coils 244
9.3.2 Thin-Film Interconnects 245
9.3.3 MR-Safe Thin Film Interconnects 246
9.4 Thin-Film Device Fabrication 249
9.4.1 Design and Modeling 249
9.4.2 Materials and Fabrication 249
9.4.3 Mechanical Performance 251
9.4.4 Electrical Performance 252
9.5 Magnetic Resonance Imaging 255
9.5.1 Imaging with Resonant Detectors 255
9.5.2 Imaging with EBG Detectors 256
9.5.3 Imaging with MI Detectors 257
9.6 Conclusions 258
Acknowledgments 259
References 259
10 Microcoils for BroadbandMultinuclei Detection 265
Jens Anders and Aldrik H. Velders
10.1 Introduction 265
10.1.1 NMR Microcoils 266
10.1.2 Broadband NMR Microcoils 267
10.2 Microcoil-Based Broadband Probe NMR Spectroscopy 268
10.2.1 Broadband Coil, Chip, and Probe Setup 269
10.2.2 Non-tuned Broadband Planar Transceiver Coil NMR Data 269
10.2.2.1 Homonuclear 1D NMR Experiments 269
10.2.2.2 Heteronuclear 1D NMR Experiments 273
10.2.2.3 Homo- and Heteronuclear 2D NMR Experiments 273
10.2.3 Questions Arising for Broadband NMR 273
10.3 An Engineer’s Answers to the Questions 274
10.3.1 General Remarks 274
10.3.2 Coils 274
10.3.3 Impedance Matching and Front-end Electronics 278
10.3.4 Answers to the Questions 287
10.3.5 Remaining Spectrometer Electronics 289
10.4 Conclusion and Outlook 289
Acknowledgment 290
References 291
11 Microscale Hyperpolarization 297
Sebastian Kiss, Lorenzo Bordonali, Jan G. Korvink, and Neil MacKinnon
11.1 Introduction 297
11.2 Theory 301
11.2.1 Dynamic Nuclear Polarization 301
11.2.1.1 Polarization Transfer and DNP Mechanisms 301
11.2.1.2 DNP Instrumentation 302
11.2.1.3 Challenges in DNP Instrumentation 303
11.2.2 para-Hydrogen-Induced Hyperpolarization 304
11.2.3 Spin-Exchange by Optical Pumping 309
11.3 Microtechnological Approaches 312
11.3.1 DNP 312
11.3.1.1 Microtechnology for High-Field DNP Resonators 314
11.3.1.2 Microresonators for Low- and Intermediate-Field DNP 318
11.3.1.3 Microfluidics and DNP Resonators 322
11.3.2 PHIP 323
11.3.2.1 Gas-Phase Characterization of Reactors and Fluidic Networks 324
11.3.2.2 Micro-PHIP in the Liquid Phase 327
11.3.2.3 SABRE: A Micro-NMR Compatible PHIP Technique? 330
11.3.2.4 Catalyst Solubility inWater 331
11.3.2.5 Quantification 331
11.3.2.6 High-Field SABRE 332
11.3.3 Micro-SEOP for Nuclear Hyperpolarization 333
11.4 Conclusion 337
References 338
12 Small-Volume Hyphenated NMR Techniques 353
Andrew Webb
12.1 Different Modes of Hyphenation 353
12.2 Types of Radio-Frequency Coils Used for Small-Scale Hyphenation 355
12.3 Hyphenation of NMR and Pressure-Driven Microseparations 357
12.3.1 Capillary High-Pressure Liquid Chromatography 357
12.3.2 Capillary Gas Chromatography 358
12.4 Electrically Driven Microseparations 359
12.4.1 Capillary Electrophoresis NMR 360
12.4.2 Capillary Isotachophoresis NMR 362
12.5 Off-Line Hyphenation of Microsamples with MicrocoilmDetection 363
12.6 Continuous Monitoring of In Situ Biological Systems 368
12.7 Studies of Microfluidic Mixing and Reaction Kinetics 368
12.8 Measurement of Flow Profiles in Flow Cells and Microchannels 370
12.9 Conclusion 372
References 372
13 Force-Detected Nuclear Magnetic Resonance 381
Martino Poggio and Benedikt E. Herzog
13.1 Introduction 381
13.2 Motivation 381
13.3 Principle 382
13.4 Force versus Inductive Detection 384
13.5 Early Force-Detected Magnetic Resonance 386
13.6 Single-Electron MRFM 389
13.7 Toward Nano-MRI with Nuclear Spins 390
13.7.1 Improvements to Micro-fabricated Components 391
13.7.2 MRI with Resolution Better than 100nm 391
13.7.3 Nanoscale MRI of Virus Particles 392
13.7.4 Imaging Organic Nanolayers 396
13.8 Paths Toward Continued Improvement 398
13.8.1 Magnetic Field Gradients 398
13.8.2 Mechanical Transducers 400
13.8.3 Measurement Protocols 405
13.8.4 Nano-MRI with a Nanowire Force Sensor 408
13.9 Comparison to Other Techniques 412
13.10 Outlook 414
13.11 Conclusion 416
References 416
Index 421
