Magnetic Resonance Imaging The Basics

Magnetic resonance imaging (MRI) is a rapidly developing field in basic applied science and clinical practice. Research efforts in this area have already been recognized with five Nobel prizes awarded to seven Nobel laureates in the past 70 years. Based on courses taught at The Johns Hopkins University, Magnetic Resonance Imaging: The Basics provides a solid introduction to this powerful technology. The book begins with a general description of the phenomenon of magnetic resonance and a brief summary of Fourier transformations in two dimensions. It examines the fundamental principles of physics for nuclear magnetic resonance (NMR) signal formation and image construction and provides a detailed explanation of the mathematical formulation of MRI. Numerous image quantitative indices are discussed, including (among others) signal, noise, signal-to-noise, contrast, and resolution. The second part of the book examines the hardware and electronics of an MRI scanner and the typical measurements and simulations of magnetic fields. It introduces NMR spectroscopy and spectral acquisition and imaging techniques employing various pulse sequences. The final section explores the advanced imaging technique of parallel imaging. Structured so that each chapter builds on the knowledge gained in the previous one, the book is enriched by numerous worked examples and problem sets with selected solutions, giving readers a firm grasp of the foundations of MRI technology.

Fourier Transformations Mathematical Representation of Images Continuous Images Delta Function Separable Images Linear Shift Invariant (LSI) Systems Cascade Systems Stability Fourier Transformation and Inverse FT Properties of Fourier Transformations Frequency Response Discrete Images and Systems Separable Images Linear Shift Invariant Systems Frequency Response—Point Spread Sequence Discrete Fourier Transform and Its Inverse Properties of Discrete Fourier Transforms Fundamentals of Magnetic Resonance Imaging Quantum Mechanical Description of NMR: Energy Level Diagrams Boltzmann Statistics Pulsed and Continuous Wave NMR Spin Quantum Numbers and Charge Densities Angular Momentum and Precession Overview of MR Instrumentation The Classical View of NMR—A Macroscopic Approach Rotating Frame and Laboratory Frame RF Excitation and Detection Molecular Spin Relaxation—Free Induction Decay T1 and T2 Measurements Relaxation Times in Biological Tissues Molecular Environment and Relaxation Biophysical Aspects of Relaxation Times Spectral Density and Correlation Times T1 and T2 Relaxation Quadrupolar Moments Fundamentals of Magnetic Resonance II: Imaging Magnetic Field Gradients Spin–Warp Imaging and Imaging Basics Slice Selection Multislice and Oblique Excitations Frequency Encoding Phase Encoding Fourier Transformation and Image Reconstruction Fundamentals of Magnetic Resonance III: The Formalism of k-Space MRI Signal Formulation k-Space Formalism and Trajectories Concept of Pulse Sequences Echo Planar Imaging Pulse Sequences T1, T2, and Proton Density-Weighted Images Saturation Recovery, Spin–Echo, Inversion Recovery Gradient–Echo Imaging: FLASH, SSFP, and STEAM Bloch Equation Formulation and Simulations Technical Limits and Safety Introduction to Instrumentation Magnets and Designs Stability, Homogeneity, and Fringe Field Gradient Coils RF Coils RF Decoupling B Field Distributions and Simulations Safety Issues Tour of an MRI Facility Hardware Imaging Generation of MRI Images Safety Signal, Noise, Resolution, and Image Contrast Signal and Noise Sources in MRI Signal to Noise Ratio Contrast-to-Noise Ratio Tissue Parameters and Image Dependence Imaging Parameters and Image Dependence Resolution Spectroscopy and Spectroscopic Imaging Introduction to NMR Spectroscopy Fundamental Principles Localized Spectroscopy Imaging Equation and Spectroscopic Imaging Advanced Imaging Techniques: Parallel Imaging Introduction to Parallel Imaging Parallel Imaging Fundamentals Transmit Phased Arrays Problem Sets Multiple Choice Questions Solutions to Selected Problems Answers to Multiple Choice Questions Glossary Bibliography Index

Christakis Constantinides, PhD joined the faculty of the Mechanical Engineering Department at the University of Cyprus in September 2005. He has also acted as a consultant to his start-up firm, Chi-Biomedical Ltd. ever since. His specific research interest focuses on the study of cardiac mechanical function, computational and tissue structure modeling and characterization, hardware design, and functional and cellular tracking methods using MRI. The goal of his research efforts is the complete characterization of the electromechanical function of the heart in small animals and humans, aiming to promote the understanding of mechanisms of human disease that is predominantly underlined by genetic causes.