MRI in Practice
Description
* The leading MRI reference book and study guide.
* Now with a greater focus on the physics behind MRI.
* Offers, for the first time, equations and their explanations and scan tips.
* Brand new chapters on MRI equipment, vascular imaging and safety.
* Presented in full color, with additional illustrations and high-quality MRI images to aid understanding.
* Includes refined, updated and expanded content throughout, along with more learning tips and practical applications.
* Features a new glossary.
MRI in Practice is an important text for radiographers, technologists, radiology residents, radiologists, and other students and professionals working within imaging, including medical physicists and nurses.
More details
Other editions
Additional editions
Persons
ABOUT THE AUTHORS
CATHERINE WESTBROOK, Senior Lecturer and Course Leader, MSc Magnetic Resonance Imaging (MRI), Anglia Ruskin University, Cambridge, UK.
JOHN TALBOT, Senior Lecturer, MSc Magnetic Resonance Imaging (MRI), Anglia Ruskin University, Cambridge, UK.
Content
Preface to the Fifth Edition ix
Acknowledgments xi
List of Acronyms xiii
Equation symbols xvii
About the Companion Website xix
Chapter 1 Basic principles 1
Introduction 1
Atomic structure 2
Motion in the atom 2
MR active nuclei 4
The hydrogen nucleus 5
Alignment 6
Net magnetic vector (NMV) 8
Precession and precessional (Larmor) frequency 10
Precessional phase 13
Resonance 13
MR signal 18 The free Induction decay(FDI) signal 20 Pulse timing parameters 22
Chapter 2 Image weighting and contrast 24
Introduction 24
Image contrast 25
Relaxation 25
T1 recovery 26
T2 decay 27
Contrast mechanisms 31
>
T1 contrast 36
T2 contrast 40
Proton density contrast 41
Weighting 42
Other contrast mechanisms 51
Chapter 3 Spin echo pulse sequences 58
Introduction 58
RF rephasing 59
Conventional spin echo 65
Fast or turbo spin echo FSE/TSE) 68
Inversion recovery (IR) 78
Short tau inversion recovery (STIR) 82
Fluid attenuated inversion recovery (FLAIR) 84
Chapter 4 Gradient echo pulse sequences 89
Introduction 89
Variable flip angle 90
Gradient rephasing 91
Weighting in gradient echo pulse sequences 94
Coherent or rewound gradient echo 106
Incoherent or spoiled gradient echo 109
Reverse-echo gradient echo 113
Balanced gradient echo 119
Fast gradient echo 122
Echo planar imaging (EPI) 122
Chapter 5 Spatial encoding 128
Introduction 128
Mechanism of gradients 129
Gradient axes 134
Slice-selection 135
Frequency encoding 142
Phase encoding 145
Bringing it all together - pulse sequence timing 152
Chapter 6 k-space 158
Introduction 158
Part 1 - what is k-space? 159
Part 2 - how are data acquired and how are images created from this data? 165
Part 3 -some important facts about k-space 184
Part 4: how do pulse sequences fill k-space? 197
Part 5: options that fill k-space 199
Chapter 7 Protocol optimization 209
Introduction 209
Signal-to-noise ratio (SNR) 210
Contrast-to-noise ratio (CNR) 226
Spatial resolution 232
Scan time 237
Trade-offs 238
Protocol development and modification 238
Chapter 8 Artefacts 240
Introduction 242
Phase mismapping 243
Aliasing 253
Chemical shift artefact 261
Out-of-phase signal cancellation 265
Magnetic susceptibility artefact 269
Truncation artefact 272
Cross-excitation/cross-talk 273
Zipper artefact 275
Shading artefact 276
Moiré artefact 277
Magic angle 279
Equipment faults 280
Flow artefacts 280
Flow-dependent (non-contrast enhanced) angiography 298
Black-blood imaging 303
Phase contrast MRA 304
Chapter 9 Instrumentation 311
Introduction 311
Magnetism 313
Scanner configurations 315
Magnet system 318
Magnet shielding 326
Shim system 328
Gradient system 330
RF system 337
Patient transport system 343
Computer system and graphic user interface 344
Chapter 10 MRI safety 346
Introduction (and disclaimer) 346
Definitions used in MRI safety 347
Psychological effects 350
The spatially-varying static field 351
Electromagnetic (radiofrequency) fields 357
Time-Varying Gradient Magnetic Fields 363
Cryogens 365
Safety tips 367
Additional resources 368
Glossary 370
Index 387
Acronyms
Generic Siemens GE Philips Hitachi Toshiba Pulse sequences Conventional spin-echo (SE) SE SE SE SE SE Turbo spin-echo (TSE) TSE FSE TSE FSE FSE Single-shot TSE (SS-TSE) HASTE SS-FSE SS-TSE SS-FSE FASE TSE (with restoration pulse) RESTORE FRFSE DRIVE driven equilibrium FSE T2 Puls FSE Inversion recovery (IR) IR IR/MPIR IR IR IR Fast inversion recovery TIR Fast IR IR-TSE IR IR Short tau IR (STIR) STIR STIR STIR STIR fast STIR Fluid-attenuated IR (FLAIR) turbo dark fluid FLAIR FLAIR FLAIR fast FLAIR Gradient-echo (GRE) GRE GRE FFE GE field echo Coherent gradient-echo FISP GRASS FFE rephased SARGE SSFP Incoherent gradient-echo FLASH SPGR T1 FFE spoiled SARGE fast FE Reverse-echo gradient-echo PSIF SSFP T2 FFE time-reversed SARGE - Balanced gradient-echo true FISP FIESTA BFFE balanced SARGE true SSFP Echo-planar imaging (EPI) EPI EPI EPI EPI EPI Double-echo steady state DESS - - - - Balanced dual excitation CISS FIESTA-C - phase balanced SARGE - Multi-echo-data-image-combination MEDIC MERGE MFFE - - Fast gradient-echo turbo FLASH fast GRE, fast SPGR TFE RGE Fast FE Hybrid sequence TGSE - GRASE - Hybrid EPI Contrast parameters Repetition time (TR) TR TR TR TR TR Time to echo (TE) TE TE TE TE TE Time from inversion (TI) TI TI TI TI TI Flip angle flip angle flip angle flip angle flip angle Flip angle Number of echoes (in TSE) turbo factor ETL turbo factor shot factor ETL b factor/value b factor b factor b factor b factor b factor Geometry parameters Field of view (FOV) FOV (mm) FOV (cm) FOV (mm) FOV (mm) FOV (mm) Rectangular FOV FOV phase PFOV rectangular FOV rectangular FOV rectangular FOV Slice gap distance factor gap gap slice interval gap Data acquisition parameters Averages average NEX NSA NSA NSA Bandwidth bandwidth (Hz/pixel) receive bandwidth (KHz) fat water shift (pixel) bandwidth (KHz) bandwidth (KHz) Variable bandwidth optimized bandwidth variable bandwidth optimized bandwidth variable bandwidth matched bandwidth Partial averaging half Fourier fractional NEX half scan half scan AFI Partial echo asymmetric echo partial echo partial echo half echo matched bandwidth Parallel imaging (image based) mSENSE ASSET SENSE RAPID SPEEDER Parallel imaging (k-space based) GRAPPA ARC - - - Artifact reduction techniques Radial k-space filling BLADE PROPELLOR multiVane RADAR JET Gradient moment rephasing GMR/flow comp flow comp flow comp/FLAG GR FC Presaturation pre SAT Sat REST Pre SAT Pre SAT Moving sat pulse travel SAT walking SAT travel REST Sequential pre SAT BFAST Fat saturation fat SAT chem SAT SPIR Fat Sat MSOFT Out-of-phase imaging DIXON IDEAL ProSET Water excitation PASTA Respiratory...
