Nuclear Magnetic Resonance Imaging Technology

Nuclear magnetic resonance is now widely used in hospitals and research laboratories worldwide for medical purposes. Biomedical Magnetic Resonance Imaging is the first book to concentrate on how the instrumentation involved works rather than on the applications of the technique. In order to help the reader fully understand how an NMR imaging or spectroscopy system works the book takes an in-depth look at the principles behind the different components of the machine. Starting with a short history of the developments of nuclear magnetic resonance, the authors go on to describe all the different areas of instrumentation, such as the receiver and the magnet. A full explanation of the electronics and computer hardware and software appears for the first time in book form, completing this thorough view of an NMR system. Each chapter builds from a basic to a more sophisticated level of understanding and numerous illustrations help the reader to grasp the concepts. For the most part, mathematical descriptions appear at the ends of chapters, to place the emphasis of the book on the understanding of underlying principles. Biomedical Magnetic Resonance Imaging will be invaluable to all medical physicists, technicians, researchers and engineers working with NMR, containing as it does both theoretical and practical data to enable users to get the most out of their machines.

Magnetic resonance systems are used in almost every academic and industrial chemistry, physics and biochemistry department, as well as being one of the most important imaging modalities in clinical radiology. The design of such systems has become increasingly sophisticated over the years. Static magnetic fields increase continuously, large-scale arrays of receive elements are now ubiquitous in clinical MRI, cryogenic technology has become commonplace in high resolution NMR and is expanding rapidly in preclinical MRI, specialized high strength magnetic field gradients have been designed for studying the human connectome, and the commercial advent of ultra-high field human imaging has required new types of RF coils and static shim coils together with extensive electromagnetic simulations to ensure patient safety. This book covers the hardware and engineering that constitutes a magnetic resonance system, whether that be a high-resolution liquid or solid state system for NMR spectroscopy, a preclinical system for imaging animals or a clinical system used for human imaging. Written by a team of experts in the field, this book provides a comprehensive and instructional look at all aspects of current magnetic resonance technology, as well as outlooks for future developments.

This volume represents the primary lectures of the NATO Advanced Study Institute (ASI) on "Nuclear Magnetic Resonance in Modern Technology," which was held at Sarigerme Park (near the Dalaman Airport) on the southern Aegean shore of Turkey from August 23 to September 4, 1992. As indicated in the title, this ASI was aimed at examining, displaying, and perhaps influencing, the role of nuclear magnetic resonance (NMR) in modern technological activity. The lectures summarized in this volume and the numerous short contributed talks and posters were primarily aimed at the question, "What is NMR doing in support of modern technology?" During the main discussion periods and the numerous small scheduled meetings of specific interest groups this same topic was also addressed, along with questions like, "What could or should NMR be doing in support of modern technology?" With this kind of subject orientation, the organizers attempted to include a large participation at the ASI from scientists and engineers from diverse private industries in which NMR does, or perhaps should, play a substantial role in supporting or optimizing technology. Perhaps because of a combination of worldwide industrial contractions and residual corporate nervousness regarding the then recent Gulf War (which caused a one-year postponement of this ASI), the participation from private industry was numerically disappointing. We hope that this book will serve to bring the role of NMR in modern industry to the attention of numerous industrial scientists and engineers who were unable to attend the AS!.

This book is designed to introduce the reader to the field of NMR/MRI at very low magnetic fields, from milli-Tesla to micro-Tesla, the ultra-low field (ULF) regime. The book is focused on applications to imaging the human brain, and hardware methods primarily based upon pre-polarization methods and SQUID-based detection. The goal of the text is to provide insight and tools for the reader to better understand what applications are best served by ULF NMR/MRI approaches. A discussion of the hardware challenges, such as shielding, operation of SQUID sensors in a dynamic field environment, and pulsed magnetic field generation are presented. One goal of the text is to provide the reader a framework of understanding the approaches to estimation and mitigation of low signal-to-noise and long imaging time, which are the main challenges. Special attention is paid to the combination of MEG and ULF MRI, and the benefits and challenges presented by trying to accomplish both with the same hardware. The book discusses the origin of unique relaxation contrast at ULF, and special considerations for image artifacts and how to correct them (i.e. concomitant gradients, ghost artifacts). A general discussion of MRI, with special consideration to the challenges of imaging at ULF and unique opportunities in pulse sequences, is presented. The book also presents an overview of some of the primary applications of ULF NMR/MRI being pursued.