Über den Autor
Catherine Westbrook MSc, FHEA, PgC (HE), DCRR, CTCert, is a Senior Lecturer and postgraduate pathway leader at The Faculty of Health & Social Care, Anglia Ruskin University, Cambridge, UK where she is responsible for the postgraduate course in MRI. Catherine is also an independent teaching consultant lecturing on the MRI in Practice Course and other renowned international courses and conferences. She is also the author of Handbook of MRI Technique and MRI at a Glance, both published by Wiley.
Carolyn Kaut Roth RT (R) (MR) (CT) (M) (CV), FSMRT, is the CEO of Imaging Education Associates, Berwyn, Pennsylvania, USA, delivering a wide variety of learning resources in MRI and other imaging modalities. John Talbot MSc, FHEA, PgC (HE), DCRR, is Senior Lecturer at The Faculty of Health & Social Care, Anglia Ruskin University, Cambridge, UK, where he is responsible for delivery of undergraduate and postgraduate modules. John is also an independent teaching consultant lecturing on the MRI in Practice Course and developing the companion website animations.
Foreword ixrnPreface to the Fourth Edition xirnAcknowledgments xiiirnChapter 1 Basic principles 1rnIntroduction 1rnAtomic structure 1rnMotion in the atom 2rnMR active nuclei 2rnThe hydrogen nucleus 4rnAlignment 4rnPrecession 8rnThe Larmor equation 9rnResonance 11rnThe MR signal 15rnThe free induction decay signal (FID) 16rnRelaxation 16rnT1 recovery 16rnT2 decay 16rnPulse timing parameters 19rnChapter 2 Image weighting and contrast 21rnIntroduction 21rnImage contrast 21rnContrast mechanisms 22rnRelaxation in diff erent tissues 23rnT1 contrast 25rnT2 contrast 27rnProton density contrast 27rnWeighting 29rnT2* decay 31rnIntroduction to pulse sequences 34rnChapter 3 Encoding and image formation 59rnEncoding 59rnIntroduction 59rnGradients 60rnSlice selection 62rnFrequency encoding 65rnPhase encoding 69rnSampling 73rnData collection and imagernformation 79rnIntroduction 79rnK space description 80rnK space fi lling 81rnFast Fourier transform (FFT) 86rnImportant facts about K space 90rnK space traversal and gradients 96rnOptions that fill K space 98rnTypes of acquisition 101rnChapter 4 Parameters and trade-offs 103rnIntroduction 103rnSignal to noise ratio (SNR) 104rnContrast to noise ratio (CNR) 123rnSpatial resolution 126rnScan time 131rnTrade-offs 134rnDecision making 134rnVolume imaging 137rnChapter 5 Pulse sequences 140rnIntroduction 140rnSpin echo pulse sequences 141rnConventional spin echo 141rnFast or turbo spin echo 143rnInversion recovery 151rnFast inversion recovery 157rnSTIR (short tau inversion recovery) 157rnFLAIR (fluid attenuated inversion recovery) 159rnIR prep sequences 163rnGradient echo pulse sequences 164rnConventional gradient echo 164rnThe steady state and echo formation 166rnCoherent gradient echo 169rnIncoherent gradient echo (spoiled) 172rnSteady state free precession (SSFP) 175rnBalanced gradient echo 179rnFast gradient echo 185rnSingle shot imaging techniques 186rnParallel imaging techniques 193rnChapter 6 Flow phenomena 198rnIntroduction 198rnThe mechanisms of flow 198rnFlow phenomena 200rnTime of flight phenomenon 200rnEntry slice phenomenon 203rnIntra-voxel dephasing 206rnFlow phenomena compensation 207rnIntroduction 207rnEven echo rephasing 207rnGradient moment rephasing (nulling) 207rnSpatial pre-saturation 210rnChapter 7 Artefacts and their compensation 225rnIntroduction 225rnPhase mismapping 225rnAliasing or wrap around 234rnChemical shift artefact 243rnOut of phase artefact (chemical misregistration) 244rnTruncation artefact 249rnMagnetic susceptibility artefact 250rnCross-excitation and cross-talk 252rnZipper artefact 255rnShading artefact 256rnMoiré artefact 256rnMagic angle 257rnChapter 8 Vascular and cardiac imaging 261rnIntroduction 261rnConventional MRI vascular imaging techniques 262rnMagnetic resonance angiography (MRA) 269rnCardiac MRI 290rnCardiac gating 291rnPeripheral gating 298rnPseudo-gating 300rnMultiphase cardiac imaging 300rnCiné 301rnSPAMM 304rnChapter 9 Instrumentation and equipment 307rnIntroduction 307rnMagnetism 309rnPermanent magnets 312rnElectromagnets 314rnSuperconducting electromagnets 317rnFringe fields 321rnShim coils 322rnGradient coils 323rnRadio frequency (RF) 330rnPatient transportation system 337rnMR computer systems and the user interface 337rnChapter 10 MRI safety 341rnIntroduction 341rnGovernment guidelines 342rnSafety terminology 343rnHardware and magnetic field considerations 345rnRadio frequency fields 346rnGradient magnetic fields 349rnThe main magnetic field 351rnProjectiles 355rnSiting considerations 357rnMRI facility zones 358rnSafety education 360rnProtecting the general public from the fringe field 360rnImplants and prostheses 361rnDevices and monitors in MRI 367rnPacemakers 367rnPatient conditions 368rnSafety policy 369rnSafety tips 370rnReference 371rnChapter 11 Contrast agents in MRI 372rnIntroduction 372rnMechanism of action of contrast agents 373rnMolecular tumbling 373rnDipole-dipole interactions 375rnMagnetic susceptibility 376rnRelaxivity 378rnGadolinium safety 380rnOther contrast agents 383rnCurrent applications of gadolinium contrast agents 385rnConclusion 393rnChapter 12 Functional imaging techniques 396rnIntroduction 396rnDiff usion weighted imaging (DWI) 397rnPerfusion imaging 400rnSusceptibility weighting (SWI) 404rnFunctional imaging (fMRI) 404rnInterventional MRI 405rnMR spectroscopy (MRS) 407rnWhole body imaging 410rnMR microscopy (MRM) 411rnGlossary 413rnIndex 427
Since the first edition was published in 1993, the book has become the standard text for radiographers, technologists, radiology residents, radiologists and even sales representatives on the subject of magnetic resonance imaging. This text is essential reading on postgraduate courses. Furthermore MRI in Practice has come to be known as the number one reference book and study guide in the areas of MR instrumentation, principles, pulse sequences, image acquisition, and imaging parameters for the advanced level examination for MRI offered by the American Registry for Radiologic Technologists (ARRT) in the USA.rnThe book explains in clear terms the theory that underpins magnetic resonance so that the capabilities and operation of MRI systems can be fully appreciated and maximised. This fourth edition captures recent advances, and coverage includes: parallel imaging techniques and new sequences such as balanced gradient echo.rnBuilding on the success of the first three editions, the fourth edition has been fully revised and updated. It also now has a companion website which hosts animated versions of a selection of illustrations in the book to aid with the reader's comprehension of some of the more difficult concepts. The website also hosts over 200 interactive self-assessment exercises to help the reader test their understanding.