Table Of ContentMagnetic Resonance Imaging
Theory and Practice
Springer-Verlag Berlin Heidelberg GmbH
Marinus T. Vlaardingerbroek Jacques A. den Boer
Magnetic Resonance Imaging
Theory and Practice
With a Foreword by Freek Knoet
and a Historical Introduction
by Andre Luiten
Second, Revised and Enlarged Edition
and 166 Figures and 56 Image Sets
, Springer
Dr. Ir. Marinus T. Vlaardingerbroek
Blaarthemseweg 49
NL-5502 JS Veldhoven, The Netherlands
Dr. Ir. Jacques A. den Boer
Zweerslaan 3
NL-5691 GN Son, The Netherlands
Cover Figure: Front view of an MRI System. Modern system design emphasizes
patient comfort and accessibility.
Library of Congress Cataloging-in-Publication Data.
Vlaardingerbroek, Marinus T., 1931-. Magnetic resonance imaging: theory and practice I Marinus T. Vlaardinger
broek; Jaques A. den Boer; with a foreword by Freek Knoel. -2nd, rev. and en!. ed. p. cm. Includes bibliographical
references and index.
ISBN 978-3-662-03802-4 ISBN 978-3-662-03800-0 (eBook)
DOI 10.1007/978-3-662-03800-0
1. Magnetic resonance imaging. I. Boer, Jacques A.
den, 1938-. II. Title. RC78.7-N83VS3 1999 616.ois48--dc2 99-36438
This work is subject to copyright. All rights are reserved, whether the whole or part of the material is
concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broad
casting, reproduction on microfilm or in any other way, and storage in data banks. Duplication of this
publication or parts thereof is permitted only under the provisions of the German Copyright Law of
September 9, 1965, in its current version, and permission for use must always be obtained from
Springer-Verlag Berlin Heidelberg GmbH.
Violations are liable for prosecution under the German Copyright Law.
© Springer-Verlag Berlin Heidelberg 1996, 1999
Originally published by Springer-Verlag Berlin Heidelberg New York in 1999
Softcover reprint of the hardcover 2nd edition 1999
The use of general descriptive names, registered names, trademarks, etc. in this publication does not
imply, even in the absence of a specific statement, that such names are exempt from the relevant pro
tective laws and regulations and therefore free for general use.
Typesetting: Satztechnik Katharina Steingraeber, Heidelberg
Cover design: design & production GmbH, Heidelberg
SPIN 10678295 55/3144/tr - 5 4 3 2 1 0 - Printed on acid-free paper
Foreword
When retired it is a blessing if one has not become too tired by the strain
of one's professional career. In the case of our retired engineer and scientist
Rinus Vlaardingerbroek, however, this is not only a blessing for him person
ally, but also a blessing for us in the field of Magnetic Resonance Imaging as
he has chosen the theory of MRI to be the work-out exercise to keep himself
in intellectual top condition. An exercise which has worked out very well and
which has resulted in the consolidated and accessible form of the work of
reference now in front of you.
This work has become all the more lively and alive by illustrations with
live images which have been added and analysed by clinical scientist Jacques
den Boer.
We at Philips Medical Systems feel proud of our comakership with the
authors in their writing of this book. It demonstrates the value we share
with them, which is "to achieve clinical superiority in MRI by quality and
imagination" .
During their careers Rinus Vlaardingerbroek and Jacques den Boer have
made many contributions to the superiority of Philips MRI Systems. They
have now bestowed us with a treasure offering benefits to the MRI community
at large and thereby to health care in general: a much needed non-diffuse
textbook to help further advance the diffusion of MRI.
Freek Knoet
Director of Magnetic Resonance
Philips Medical Systems
Preface to the First Edition
Alles sollte so einfach wie moglich
gemacht werden, aber nicht einfacher.
Albert Einstein
Since the late 1940s the phenomenon "Nuclear Magnetic Resonance" has been
known from the work of Bloch, Purcell, and many others. The phenomenon
is based on the magnetic properties of some nuclei. When these nuclei are
placed in a magnetic field, they can absorb electromagnetic radiation of a
very distinct energy, E, and, since E = hw, of a distinct frequency, w, and
re-emit this energy subsequently during their relaxation back to the original
equilibrium situation. Nuclear magnetic resonance became an important tool
in the study of the composition of chemical compounds and, in later years,
also for the physical study of matter and for biochemical studies. The Nobel
Prize was awarded twice for contributions to the knowledge of nuclear mag
netic resonance: in 1952 to Felix Bloch of Stanford University and Edward
Purcell of Harvard University, and in 1991 to Edward R. Ernst from Zurich.
In March 1973 Lauterbur published his paper "Image Formation by In
duced Local Interaction" in Nature and introduced the idea that nuclear
magnetic resonance can be used for medical diagnostic imaging. This was
achieved by adding to the homogeneous magnetic field (in which the nuclear
magnetic resonance takes place) small position-dependent (gradient) mag
netic fields, which make the resonance frequency position dependent. Now
the origin of the re-emitted radiation can be traced back on the basis of the
emitted frequency, which makes, in principle, imaging possible. Lauterbur's
work was preceeded by a patent by Damadian in 1972, in which the clinical
use of NMR was anticipated. These inventions triggered enormous activity
in realizing nuclear magnetic resonance systems for use in hospitals and in
the application of nuclear magnetic resonance to medical diagnostics. The
term "nuclear" is not commonly used because of its association with nuclear
warefare and nuclear radiation. The accepted name for the new imaging tech
nique is magnetic resonance imaging. Only a quarter of a century after the
invention of MRI one may expect that in the developed countries there will
be about one MRI system for every 105 inhabitants.
Of the many papers published nowadays on MRI (about 20 000 per year),
only a small scattered minority deals with the physics of MRI. Still, the num
ber of new ideas in this latter field is large, and in each case a good knowledge
of the basic theoretical concepts of MRI is necessary to understand them. Al
though there are many excellent books and papers treating aspects of MRI
theory, it is difficult (but not impossible) to obtain from the available litera-
VIII Preface to the First Edition
ture a coherent survey of the mathematical description of MRI. The majority
of MRI literature deals with the application of MRI to medical diagnostics,
for which a qualitative description of the MRI physics is considered to be
sufficient. This attitude has been prompted by the fact that the main in
terest in the application of MRI comes - of course - from medical doctors,
who are not in the first place interested in a quantitative physical description
of scan methods, but certainly also because early MRI systems had many
unpredictable properties, which made a quantitative understanding of the
imaging capabilities unrewarding.
However, in the last decade the reliability and reproducibility of MRI
systems has improved considerably and it may be expected that the quan
titative theoretical prediction of the results will become increasingly useful.
So, both for the quantitative interpretation of image contrast and for the de
sign or understanding of the many new imaging methods, which impose new
(higher) requirements on future system design, a quantitative, hence math
ematical, description of the physics of MRI is of much value. We think here
of new applications such as ultra fast dynamic imaging, functional imaging,
interventional imaging, the influence of contrast agents and their dynamics
in different applications, etc. Therefore in this textbook we have undertaken
the task of developing a coherent theoretical description of MRI which can
serve as a background for a thorough understanding of recent and future
developments. Although we start with the basic theory, the textbook is not
meant for making a first acquaintance with MRI. For this goal we refer the
reader to the textbooks mentioned in Chap. I.
It is interesting to note here that many of the building blocks of the
theory that we need for our task were already available in the papers on
NMR published long before the invention of MRI in 1972 - for example in
the early works of Bloch, Purcell, Ernst, Hahn, Hinshaw, and many others.
This textbook will also present a short global description of the system
and its components, as far as this knowledge is necessary for understanding
the application capabilities of the system. The design task itself requires much
more detail and this is beyond the scope of this textbook.
The theoretical results will be illustrated with numerous MR images,
which were specially acquired for the purpose of demonstrating the effects
resulting from the MR physics, the system design, and the properties of
the sequences under consideration. The images are not taken for medical
purposes: they are usually taken from healthy volunteers. However, many
problems that are met in practice are illustrated in the image sets and are
extensively discussed in the captions. Each theoretical chapter is followed by
a number of these image sets.
The image sets in this book are all generated on Philips Gyroscan systems.
This choice means that the images shown were obtained using the particular
acquisition methods available on that system type. No guarantee can be given
of the equivalence of these methods with methods that have equal names but
Preface to the First Edition IX
are implemented in MR systems of a different make. Nor will it be neces
sary for the names of physically equivalent methods to be the same in MR
systems of various origins. Nevertheless, the physical basis of the design of
MR acquisition methods as treated in this book is valid for the MR systems
of any manufacturer. We have specified particularities of the methods used
when these could reflect a special Gyroscan idiom. Almost all the image sets
are obtained at 1.5 T, making use of volunteers. Whenever this was not true
it is stated per image set.
When writing this textbook, we assumed that the reader is familiar with
the fundamentals of Fourier analysis, for which many textbooks are available.
Also in this book there is no extended theoretical description of RF pulses,
which is worth a book by itself. RF excitation pulses are treated on the basis
of a simple linear model which gives insight into some of their fundamental
properties as far as we need them for the understanding of the measuring
sequences. For the detailed design of RF pulses with large flip angles we refer
the reader to the extensive literature on that subject.
In an appendix we propose a systematic nomenclature for the imaging
sequences. This is done jointly with Prof. E.M. Haacke, one of the authors of
another book on MRI.
Best, The Netherlands Marinus T. Vlaardingerbroek
July 1995 Jacques A. den Boer
Acknowledgements
This book evolved from the education that one of us (MTV) received from his
coworkers during the period that he acted as project leader for (mainly) 1.5 T
MRI systems. After a long career in other fields of physics and engineering
(plasma physics, microwave devices and subassemblies, lasers, etc) and in
dustrial management, he joined the MR development group with practically
no knowledge of system design in general and MRI in particular. With much
patience, colleagues undertook the task of teaching their project leader, and
this education lies at the roots of the theoretical part of this textbook. It is
in a way a modest compilation of the broad knowledge at all levels of MRI
system design, system testing, and (clinical) application of the MR depart
ment. To mention all names here would be unwieldy but the friendly lessons
of all colleagues are highly appreciated.
The writing of this textbook was further supported by a course on system
design, which we organized within the development group. Together with a
number of colleagues who specialized in the different disciplines, we prepared
notes for this course. We (the present authors) were allowed to use these notes
for the preparation of this textbook. We acknowledge the lecturers of this
course, who were also willing to criticize our text. They are: M. Duijvestijn, C.
Ham, W.v. Groningen, P. Wardenier, J. den Boef, F. Verschuren, L. Hofland,
P. Luyten, B. Pronk, H. Thithof, and G.v. Yperen. Many discussions with
J. Groen, P.v.d. Meulen, M. Fuderer, R. de Boer, M. Kouwenhoven, J.v.
Eggermond, A. Mehlkopf, and many others were very stimulating.
Part of the internal Philips course was later also presented at the Institut
fur Hochfrequenztechnik of the Rheinisch Westfiilische Technische Hochschule
(Technical University) in Aachen, Germany, where also the idea of preparing
a book on the basis of the college notes was born. We thank Prof. H.J. Schmitt
for opening the opportunity to organize this course and also the Rektor and
Senate for granting the "Lehrauftrag" (teaching assignment). We also thank
k
the students for teaching us how to explain difficult concepts such as space.
One of us (JAdB) took the task of designing and collecting image sets
for the purpose of illustrating a number of essential problems in the inter
pretation of MR images of human anatomy. The text to those images was
read carefully by J.v.d. Heuvel of the Philips MR Application department.
XII Acknowledgements
All MR images presented in this textbook are with the courtesy of Philips
Medical Systems.
Most of the images are produced especially for this book on a 1.5 Tesla,
S15 ACS (Advanced Clinical System) installed at the hospital "Medisch Spec
trum Twente" in Enschede, The Netherlands. The system was kindly made
available for this purpose by the management of this hospital. We wish to
thank the operators of this system: Dinja Ahuis-Wormgoor, Tienka Doze
man, Annie Huisman-Brouwer, Richard van der Plas, and Francis Welhuis
for their skilled and enthusiastic work. Some other images, in part at other
field strengths, were put at our disposal by K. Jansen and A. Rodenburg
of Philips Medical Systems. Finally, images made with advanced techniques
such as spiral imaging and 3D EPI were given to us by D. Jensen and D.
Holz and their colleagues at the Philips Forschungs Laboratorium in Ham
burg, Germany.
The continuous support and encouragement of the Management of the MR
department of Philips Medical Systems are highly appreciated. Especially we
thank F. Knoet, W. Blount, and M. Duijvestijn for their active support.
We have enjoyed our cooperation and apologize to our wives for the long
period during which we invested such a large part of our attention in this
book.
Marinus T. Vlaardingerbroek
Jacques A. den Boer
