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MRI in Practice continues to be the number one reference book and study guide for the registry review examination for MRI offered by the American Registry for Radiologic Technologists (ARRT). This latest edition offers in-depth chapters covering all core areas, including: basic principles, image weighting and contrast, spin and gradient echo pulse sequences, spatial encoding, k-space, protocol optimization, artefacts, instrumentation, and MRI safety.





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.

MRI in Practice, 5th Edition

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





Relaxation in different tissues 32





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 242





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





Moire 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