Electromagnetics in Magnetic Resonance Imaging

Author: Christopher M. Collins
Publisher: Morgan & Claypool Publishers
ISBN: 9781681740836
Release Date: 2016-03-01
Genre: Medical

In the past few decades, Magnetic Resonance Imaging (MRI) has become an indispensable tool in modern medicine, with MRI systems now available at every major hospital in the developed world. But for all its utility and prevalence, it is much less commonly understood and less readily explained than other common medical imaging techniques. Unlike optical, ultrasonic, X-ray (including CT), and nuclear medicine-based imaging, MRI does not rely primarily on simple transmission and/or reflection of energy, and the highest achievable resolution in MRI is orders of magnitude smaller that the smallest wavelength involved. In this book, MRI will be explained with emphasis on the magnetic fields required, their generation, their concomitant electric fields, the various interactions of all these fields with the subject being imaged, and the implications of these interactions to image quality and patient safety. Classical electromagnetics will be used to describe aspects from the fundamental phenomenon of nuclear precession through signal detection and MRI safety. Simple explanations and Illustrations combined with pertinent equations are designed to help the reader rapidly gain a fundamental understanding and an appreciation of this technology as it is used today, as well as ongoing advances that will increase its value in the future. Numerous references are included to facilitate further study with an emphasis on areas most directly related to electromagnetics.

Electromagnetic Analysis and Design in Magnetic Resonance Imaging

Author: Jianming Jin
Publisher: Routledge
ISBN: 9781351453400
Release Date: 2018-02-06
Genre: Medical

This book presents a comprehensive treatment of electromagnetic analysis and design of three critical devices for an MRI system - the magnet, gradient coils, and radiofrequency (RF) coils. Electromagnetic Analysis and Design in Magnetic Resonance Imaging is unique in its detailed examination of the analysis and design of the hardware for an MRI system. It takes an engineering perspective to serve the many scientists and engineers in this rapidly expanding field. Chapters present: an introduction to MRI basic concepts of electromagnetics, including Helmholtz and Maxwell coils, inductance calculation, and magnetic fields produced by special cylindrical and spherical surface currents principles for the analysis and design of gradient coils, including discrete wires and the target field method analysis of RF coils based on the equivalent lumped-circuit model as well as an analysis based on the integral equation formulation survey of special purpose RF coils analytical and numerical methods for the analysis of electromagnetic fields in biological objects With the continued, active development of MRI instrumentation, Electromagnetic Analysis and Design in Magnetic Resonance Imaging presents an excellent, logically organized text - an indispensable resource for engineers, physicists, and graduate students working in the field of MRI.

Magnetic Resonance Imaging

Author: Stewart C. Bushong
Publisher: Elsevier Health Sciences
ISBN: 9780323014854
Release Date: 2003-01-01
Genre: Medical

Dette er en grundlæggende lærebog om konventionel MRI samt billedteknik. Den begynder med et overblik over elektricitet og magnetisme, herefter gives en dybtgående forklaring på hvordan MRI fungerer og her diskuteres de seneste metoder i radiografisk billedtagning, patientsikkerhed m.v.

Ultra High Field Magnetic Resonance Imaging

Author: Pierre-Marie Robitaille
Publisher: Springer Science & Business Media
ISBN: 0387496483
Release Date: 2007-12-31
Genre: Medical

The foundation for understanding the function and dynamics of biological systems is not only knowledge of their structure, but the new methodologies and applications used to determine that structure. This volume in Biological Magnetic Resonance emphasizes the methods that involve Ultra High Field Magnetic Resonance Imaging. It will interest researchers working in the field of imaging.

Magnetic Resonance Imaging

Author: Robert W. Brown
Publisher: John Wiley & Sons
ISBN: 9780471720850
Release Date: 2014-06-23
Genre: Medical

Preceded by Magnetic resonance imaging: physical principles and sequence design / E. Mark Haacke ... [et al.]. c1999.

Effect of Electromagnetic Field Accompanying the Magnetic Resonance Imaging on Human Heart Rate Variability a Pilot Study

Author:
Publisher:
ISBN: OCLC:1053735217
Release Date: 2018
Genre:

ABSTRACT: The effect of electromagnetic field on cardiovascular system in the literature is defined in ambiguous way. The aim of this study was to evaluate the effect of electromagnetic field on the heart rate variability (HRV) during the examination with magnetic resonance. Forty-two patients underwent Holter ECG heart monitoring for 30 minutes twice: immediately before and after the examination with magnetic resonance imaging (MRI). HRV was analysed by assessing a few selected time and spectral parameters. Is has been shown that standard deviation of NN intervals (SDNN) and very low frequency rates increased, whereas the low frequency:high frequency parameter significantly decreased following the MRI examination. These results show that MRI may affect the HRV most likely by changing the sympathetic-parasympathetic balance.

Magnetic Resonance Imaging for Groundwater

Author: Anatoly Legtchenko
Publisher: John Wiley & Sons
ISBN: 9781118649473
Release Date: 2013-12-04
Genre: Technology & Engineering

This book presents the basics of the non-invasive geophysical method for groundwater investigation, called Magnetic Resonance Sounding (MRS) or Surface Nuclear Magnetic Resonance (SNMR), and its practical application to the problems of groundwater localization and aquifer characterization. The method is based on the nuclear magnetic resonance (NMR) phenomenon and is selectively sensitive to groundwater. The main aims of the author are to teach the reader the basic principles of the method as well as to formulate consistent approximate models, leading to reasonably simple inverse problems. Containing an extensive bibliography, numerous practical and numerical examples as well as a detailed presentation of the nuts and bolts of the method based on the long-term experience of SNMR development and practical use, this book is useful for students, scientists and professional engineers working in the field of hydrogeophysics and hydrogeology. Contents 1. SNMR Imaging for Groundwater. 2. The Basics of NMR. 3. Forward Modeling. 4. Inversion. 5. Link Between SNMR and Aquifer Parameters.

Magnetic Resonance Imaging of Congenital Heart Disease

Author: Mushabbar A. Syed
Publisher: Springer Science & Business Media
ISBN: 9781447142676
Release Date: 2012-12-19
Genre: Medical

This textbook is alone in focusing on the subject of cardiac magnetic resonance (CMR) imaging in pediatric and adult patients with congenital heart disease. The topic of congenital heart disease imaging is usually relegated to a single chapter in most general CMR texts. The expanding scope of CHD warrants a text dedicated to covering CHD and CMR imaging in detail. Our proposed book aims to be a comprehensive and authoritative text on this subject. This book is be a multi-authored, illustrated text that includes supplementary access to a number of clinical videos. Authors have been selected from imaging experts in the most medically advanced areas of the world, heavily weighted by experts in the US and Europe to produce the quintessential reference in this topic.

Ultra Low Field Nuclear Magnetic Resonance

Author: Robert Kraus Jr.
Publisher: Oxford University Press
ISBN: 9780199347889
Release Date: 2014-02-26
Genre: Medical

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.

Physics of the Life Sciences

Author: Jay Newman
Publisher: Springer Science & Business Media
ISBN: 9780387772585
Release Date: 2008-10-09
Genre: Science

Each chapter has three types of learning aides for students: open-ended questions, multiple-choice questions, and quantitative problems. There is an average of about 50 per chapter. There are also a number of worked examples in the chapters, averaging over 5 per chapter, and almost 600 photos and line drawings.

Engineering Electromagnetics

Author: Nathan Ida
Publisher: Springer
ISBN: 9783319078069
Release Date: 2015-03-20
Genre: Technology & Engineering

This book provides students with a thorough theoretical understanding of electromagnetic field equations and it also treats a large number of applications. The text is a comprehensive two-semester textbook. The work treats most topics in two steps – a short, introductory chapter followed by a second chapter with in-depth extensive treatment; between 10 to 30 applications per topic; examples and exercises throughout the book; experiments, problems and summaries. The new edition includes: modifications to about 30-40% of the end of chapter problems; a new introduction to electromagnetics based on behavior of charges; a new section on units; MATLAB tools for solution of problems and demonstration of subjects; most chapters include a summary. The book is an undergraduate textbook at the Junior level, intended for required classes in electromagnetics. It is written in simple terms with all details of derivations included and all steps in solutions listed. It requires little beyond basic calculus and can be used for self-study. The wealth of examples and alternative explanations makes it very approachable by students. More than 400 examples and exercises, exercising every topic in the book Includes 600 end-of-chapter problems, many of them applications or simplified applications Discusses the finite element, finite difference and method of moments in a dedicated chapter

Magnetic Resonance Imaging in Obstetrics and Gynaecology

Author: Martin C. Powell
Publisher: Butterworth-Heinemann
ISBN: 9781483281261
Release Date: 2013-10-22
Genre: Medical

Magnetic Resonance Imaging in Obstetrics and Gynecology focuses on the potential of magnetic resonance imaging (MRI) as a major imaging modality in the management of malignant diseases in the pelvis. This text is organized into two parts encompassing 11 chapters that provide images obtained by MRI in obstetrics and gynecology. Part one deals with the distinctive features of the normal uterus and vagina and those with carcinoma. It also presents the images of the benign disease and carcinomous ovary. Part 2 considers images of the maternal anatomy, placenta, fetus, and the gestational trophoblastic neoplasia. This book is of great value to obstetricians, gynecologists, and MRI technicians.

Biological Effects of Magnetic and Electromagnetic Fields

Author: S. Ueno
Publisher: Springer Science & Business Media
ISBN: 9780585316611
Release Date: 2007-07-23
Genre: Science

The International Symposium on Biological Effects of Magnetic and Electrom- netic Fields was held from September 3-4, 1993 at Kyushu University in Fukuoka . Japan . Originally, it was only intended to be an informal gathering of many scientists who had accepted my invitation to visit Kyushu University after the XXIVth General Assembly of the International Union of Radio Science (URSI), held in Kyoto prior to our symposium . However, since so many distinguished scientists were able to come, it was decided that a more formal symposium would be possible . It was a very productive symposium and, as a result, many of the guests consented that it would be a good idea to gather all the information put forth at the meeting and have it published. In addition, although they were unfortunately unable to attend the symposium . many other distinguished scientists had also expressed their wish to contribute to this effort and, in so doing. help to increase understanding in this, as yet, relatively immature field of science . The question of both positive and negative effects of magnetic and electromagnetic fields on biological systems has become more and more important in our world today as they .