In Vivo NMR Spectroscopy

Principles and Techniques

Robin A. de Graaf

• Publisher: Wiley
• Year: 2018
• Print ISBN: 9781119382546
• eBook ISBN: 9781119382515
• Edition: 3
• Topic: Physical Sciences
• Subtopic: Spectroscopy & Spectrum Analysis

Presents basic concepts, experimental methodology and data acquisition, and processing standards of in vivo NMR spectroscopy

This book covers, in detail, the technical and biophysical aspects of in vivo NMR techniques and includes novel developments in the field such as hyperpolarized NMR, dynamic 13 C NMR, automated shimming, and parallel acquisitions. Most of the techniques are described from an educational point of view, yet it still retains the practical aspects appreciated by experimental NMR spectroscopists. In addition, each chapter concludes with a number of exercises designed to review, and often extend, the presented NMR principles and techniques.

The third edition of In Vivo NMR Spectroscopy: Principles and Techniques has been updated to include experimental detail on the developing area of hyperpolarization; a description of the semi-LASER sequence, which is now a method of choice; updated chemical shift data, including the addition of 31 P data; a troubleshooting section on common problems related to shimming, water suppression, and quantification; recent developments in data acquisition and processing standards; and MatLab scripts on the accompanying website for helping readers calculate radiofrequency pulses.

• Provide an educational explanation and overview of in vivo NMR, while maintaining the practical aspects appreciated by experimental NMR spectroscopists
• Features more experimental methodology than the previous edition
• End-of-chapter exercises that help drive home the principles and techniques and offer a more in-depth exploration of quantitative MR equations
• Designed to be used in conjunction with a teaching course on the subject

In Vivo NMR Spectroscopy: Principles and Techniques, 3 rd Edition is aimed at all those involved in fundamental and/or diagnostic in vivo NMR, ranging from people working in dedicated in vivo NMR institutes, to radiologists in hospitals, researchers in high-resolution NMR and MRI, and in areas such as neurology, physiology, chemistry, and medical biology.

1
Basic Principles

1.1 Introduction

Spectroscopy is the study of the interaction between matter and electromagnetic radiation. Atoms and molecules have a range of discrete energy levels corresponding to different, quantized electronic, vibrational, or rotational states. The interaction between atoms and electromagnetic radiation is characterized by the absorption and emission of photons with an energy that exactly matches the energy level difference between two states. Since the energy of a photon is proportional to the frequency, the different forms of spectroscopy are often distinguished on the basis of the frequencies involved. For instance, absorption and emission between the electronic states of the outer electrons typically require frequencies in the ultraviolet (UV) range, hence giving rise to UV spectroscopy. Molecular vibrational modes are characterized by frequencies just below visible red light and are thus studied with infrared (IR) spectroscopy. Nuclear magnetic resonance (NMR) spectroscopy uses radiofrequencies, which are typically in the range of 10–1000 MHz.

NMR is the study of the magnetic properties and related energies of nuclei. The absorption of radiofrequency energy can be observed when the nuclei are placed in a (strong) external magnetic field. Purcell et al. [1] at MIT, Cambridge and Bloch et al. [2–4] at Stanford simultaneously, but independently discovered NMR in 1945. In 1952, Bloch and Purcell shared the Nobel Prize in Physics in recognition of their pioneering achievements [5, 6]. At this stage, NMR was purely an experiment for physicists to determine the nuclear magnetic moments of nuclei. NMR could only develop into one of the most versatile forms of spectroscopy after the discovery that nuclei within the same molecule absorb energy at different resonance frequencies. These so‐called chemical shift effects, which are directly related to the chemical environment of the nuclei, were first observed in 1949 by Proctor and Yu [7], and independently by Dickinson [8]. The ability of NMR to provide detailed chemical information on compounds was firmly established when Arnold et al. [9] in 1951 published a high‐resolution ¹H NMR spectrum of ethanol in which separate signals from methyl, methylene, and hydroxyl protons could be clearly recognized.

In the first two decades, NMR spectra were recorded in a continuous wave mode in which the magnetic field strength or the radio frequency was swept through the spectral area of interest, while keeping the other fixed. In 1966, NMR was revolutionized by Ernst and Anderson [10] who introduced pulsed NMR in combination with Fourier transformation. Pulsed or Fourier transform NMR is at the heart of all modern NMR experiments.

The induced energy level difference of nuclei in an external magnetic field is very small when compared to the thermal energy at room temperature, making it that the energy levels are almost equally populated. As a result the absorption of photons is very low, making NMR a very insensitive technique when compared to the other forms of spectroscopy. However, the low‐energy absorption makes NMR also a noninvasive and nondestructive technique, ideally suited for in vivo measurements. It is believed that, by observing the water signal from his own finger, Bloch was the first to perform an in vivo NMR experiment. Over the following decades, NMR studies were carried out on various biological samples like vegetables and mammalian tissue preparations. Continued interest in defining and explaining the properties of water in biological tissues led to the promising report of Damadian in 1971 [11] that NMR properties (relaxation times) of malignant tumorous tissues significantly differs from normal tissue, suggesting that proton NMR may have diagnostic value. In the early 1970s, the first experiments of NMR spectroscopy on intact living tissues were reported. Moon and Richards [12] used ³¹P NMR on intact red blood cells and showed how the intracellular pH can be determined from chemical shift differences. In 1974, Hoult et al. [13] reported the first...

Table of contents

• Cover
• Table of Contents
• Preface
• Abbreviations
• Supplementary Material
• 1 Basic Principles
• 2 In Vivo NMR Spectroscopy – Static Aspects
• 3 In Vivo NMR Spectroscopy – Dynamic Aspects
• 4 Magnetic Resonance Imaging
• 5 Radiofrequency Pulses
• 6 Single Volume Localization and Water Suppression
• 7 Spectroscopic Imaging and Multivolume Localization
• 8 Spectral Editing and 2D NMR
• 9 Spectral Quantification
• 10 Hardware
• Appendix A
• Index
• End User License Agreement