Magnetic resonance elastography : physical background and medical applications / Sebastian Hirsch, Jürgen Braun, and Ingolf Sack.

Format:

Book

Author/Creator:

Hirsch, Sebastian, author.

Braun, Jürgen, author.

Sack, Ingolf, author.

Language:

English

Subjects (All):

Magnetic resonance imaging.

Physical Description:

1 online resource (453 pages) : illustrations (some color)

Edition:

1st ed.

Place of Publication:

Weinheim, Germany : Wiley-VCH, 2017.

Summary:

Magnetic resonance elastography (MRE) is a medical imaging technique that combines magnetic resonance imaging (MRI) with mechanical vibrations to generate maps of viscoelastic properties of biological tissue. It serves as a non-invasive tool to detect and quantify mechanical changes in tissue structure, which can be symptoms or causes of various diseases. Clinical and research applications of MRE include staging of liver fibrosis, assessment of tumor stiffness and investigation of neurodegenerative diseases. The first part of this book is dedicated to the physical and technological principles underlying MRE, with an introduction to MRI physics, viscoelasticity theory and classical waves, as well as vibration generation, image acquisition and viscoelastic parameter reconstruction. The second part of the book focuses on clinical applications of MRE to various organs. Each section starts with a discussion of the specific properties of the organ, followed by an extensive overview of clinical and preclinical studies that have been performed, tabulating reference values from published literature. The book is completed by a chapter discussing technical aspects of elastography methods based on ultrasound.

Contents:

Cover

Title Page

Copyright

Contents

About the Authors

Foreword

Preface

Acknowledgments

Notation

List of Symbols

Introduction

Part I Magnetic Resonance Imaging

Chapter 1 Nuclear Magnetic Resonance

1.1 Protons in a Magnetic Field

1.2 Precession of Magnetization

1.3 Relaxation

1.4 Bloch Equations

1.5 Echoes

1.6 Magnetic Resonance Imaging

Chapter 2 Imaging Concepts

2.1 k-Space

2.2 k-Space Sampling Strategies

2.3 Fast Imaging

Chapter 3 Motion Encoding and MRE Sequences

3.1 Motion Encoding

3.2 Intra-Voxel Phase Dispersion

3.3 Diffusion-Weighted MRE

3.4 MRE Sequences

Part II Elasticity

Chapter 4 Viscoelastic Theory

4.1 Strain

4.2 Stress

4.3 Invariants

4.4 Hooke's Law

4.5 Strain-Energy Function

4.6 Symmetries

4.7 Engineering Constants

4.8 Viscoelastic Models

4.9 Dynamic Deformation

4.10 Waves in Anisotropic Media

4.11 Energy Density and Flux

4.12 Shear Wave Scattering from Interfaces and Inclusions

Chapter 5 Poroelasticity

5.1 Navier's Equation for Biphasic Media

5.2 Poroelastic Signal Equation

Part III Technical Aspects and Data Processing

Chapter 6 MRE Hardware

6.1 MRI Systems

6.2 Actuators

Chapter 7 MRE Protocols

Chapter 8 Numerical Methods and Postprocessing

8.1 Noise and Denoising in MRE

8.2 Directional Filters

8.3 Numerical Derivatives

8.4 Finite Differences

Chapter 9 Phase Unwrapping

9.1 Flynn's Minimum Discontinuity Algorithm

9.2 Gradient Unwrapping

9.3 Laplacian Unwrapping

Chapter 10 Viscoelastic Parameter Reconstruction Methods

10.1 Discretization and Noise

10.2 Phase Gradient

10.3 Algebraic Helmholtz Inversion

10.4 Local Frequency Estimation

10.5 Multifrequency Inversion

10.6 k-MDEV

10.7 Finite Element Method.

10.8 Direct Inversion for a Transverse Isotropic Medium

10.9 Waveguide Elastography

Chapter 11 Multicomponent Acquisition

Chapter 12 Ultrasound Elastography

12.1 Strain Imaging (SI)

12.2 Strain Rate Imaging (SRI)

12.3 Acoustic Radiation Force Impulse (ARFI) Imaging

12.4 Vibro-Acoustography (VA)

12.5 Vibration-Amplitude Sonoelastography (VA Sono)

12.6 Cardiac Time-Harmonic Elastography (Cardiac THE)

12.7 Vibration Phase Gradient (PG) Sonoelastography

12.8 Time-Harmonic Elastography (1D/2D THE)

12.9 Crawling Waves (CW) Sonoelastography

12.10 Electromechanical Wave Imaging (EWI)

12.11 Pulse Wave Imaging (PWI)

12.12 Transient Elastography (TE)

12.13 Point Shear Wave Elastography (pSWE)

12.14 Shear Wave Elasticity Imaging (SWEI)

12.15 Comb-Push Ultrasound Shear Elastography (CUSE)

12.16 Supersonic Shear Imaging (SSI)

12.17 Spatially Modulated Ultrasound Radiation Force (SMURF)

12.18 Shear Wave Dispersion Ultrasound Vibrometry (SDUV)

12.19 Harmonic Motion Imaging (HMI)

Part IV Clinical Applications

Chapter 13 MRE of the Heart

13.1 Normal Heart Physiology

13.2 Clinical Motivation for Cardiac MRE

13.3 Cardiac Elastography

Chapter 14 MRE of the Brain

14.1 General Aspects of Brain MRE

14.2 Technical Aspects of Brain MRE

14.3 Findings

Chapter 15 MRE of Abdomen, Pelvis, and Intervertebral Disc

15.1 Liver

15.2 Spleen

15.3 Pancreas

15.4 Kidneys

15.5 Uterus

15.6 Prostate

15.7 Intervertebral Disc

Chapter 16 MRE of Skeletal Muscle

16.1 In vivo MRE of Healthy Muscles

16.2 MRE in Muscle Diseases

Chapter 17 Elastography of Tumors

17.1 Micromechanical Properties of Tumors

17.2 Ultrasound Elastography of Tumors

17.3 MRE of Tumors

Part V Outlook

Chapter A Simulating the Bloch Equations.

Chapter B Proof that Eq. (3.8) Is Sinusoidal

Chapter C Proof for Eq. (4.1)

Chapter D Wave Intensity Distributions

D.1 Calculation of Intensity Probabilities

D.2 Point Source in 3D

D.3 Classical Diffusion

D.4 Damped Plane Wave

References

Index

EULA.

Notes:

Includes bibliographical references at the end of each chapters and index.

Description based on online resource; title from PDF title page (ebrary, viewed December 14, 2016).

ISBN:

3-527-69602-4

3-527-69604-0

3-527-69601-6

OCLC:

967613862