Table Of ContentDiffusion MRI
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Diffusion MRI
Theory, Methods, and Applications
Edited by
Derek K. Jones, PhD
Director of MRI
Cardiff University Brain Research Imaging Centre (CUBRIC)
School of Psychology, Cardiff University
Cardiff, Wales
United Kingdom
1
2011
1
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Library of Congress Cataloging-in-Publication Data
Diffusion MRI : theory, methods, and applications / edited by Derek K. Jones.
p. ; cm.
Includes bibliographical references and index.
ISBN 978-0-19-536977-9 (alk. paper)
1. Brain—Magnetic resonance imaging. 2. Diffusion magnetic resonance imaging. I. Jones, Derek K.
[DNLM: 1. Diffusion Magnetic Resonance Imaging. 2. Brain Diseases—diagnosis. WN 185 D56935 2010]
RC386.6.M34D54 2010
616.8’047548—dc22
2009050107
1 3 5 7 9 8 6 4 2
Printed in the United States of America
on acid-free paper
This book is dedicated to Claire, Sam, and Millie—the most wonderful,
loving, and supportive family a man could ever wish for.
D.K.J.
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Foreword
I t is a great privilege to introduce this book devoted to diffusion white matter fi ber structure. DTI (and variants such as HARDI
MRI and it cannot arrive at a better time, as we will celebrate in or DSI) can now produce gorgeous three-dimensional color
2010 the 25th anniversary of diffusion MRI, as we know it. images of the circuitry of the brain which will be used to map,
T his very powerful method and concept was, indeed, intro- for the fi rst time, the human brain “connectome”, opening up new
duced in 1985, as well as its potential for brain imaging. Of lines of inquiry for human neuroscience and for treating brain
course, earlier works had demonstrated that molecular diffusion disorders, such as autism, schizophrenia or neurodegenerative
could be measured with NMR with the pioneering work of Hahn, diseases. More recently, diffusion MRI has also been proposed
Carr and Purcell, and most importantly Stejskal and Tanner in the as an approach to obtain images of brain function. One should
1960s. However, the possibility to localize those measurements not overlook also applications of diffusion MRI to the body,
under the form of maps of the diffusion coeffi cients of water especially for the screening of primary or secondary malignant
in tissues, especially in vivo and in the human brain, had never tumors, an approach which is fast becoming a standard.
been shown before. This might look a simple achievement, but The editor of this volume, Dr. Derek Jones is internationally
the localization of molecular diffusion (a microscopic process) known for his original contributions to the literature on white
through MRI (with a millimetric resolution) was certainly not a matter fi ber tractography with diffusion MRI. I remember well
trivial challenge, and there are still many technical outstanding my fi rst encounter with Derek at the workshop I had organized in
issues—as can be seen within the chapters of this book—as well 2002 in Saint-Malo on the “Biophysical issues of diffusion MRI:
as in the recollections from the minds of key players which are What can we measure?”. Although many aspects of this question
assembled at the end of the book. are yet unanswered (enough to keep researchers busy for life),
Since that time, diffusion MRI has been an extraordinarily tremendous progress has been made since then and the publica-
successful imaging technique (more than 130 000 entries in tion of the fi rst book on diffusion MRI in 1995. I sincerely con-
Google Scholar for ‘diffusion MRI’ at the time of this writing). gratulate Derek and his contributing authors, all well-recognized
This is not a surprise as the power of diffusion MRI resides in experts, to have made this body of knowledge available to the
its potential to probe tissue structure and function at the cellu- community. This state-of-the-art book will be of immense help to
lar level without using contrast media or ionizing radiations. Its the scientists and clinicians, experts or in training, who want to
main clinical domain of application has been with neurological improve their skills in diffusion MRI.
disorders, especially for the management of acute stroke patients I wish Derek great success with this book which should
in the emergency room when treatment is still possible and thus defi nitely stimulate and inspire readers.
saving patients from permanent brain damage. It has also rap-
idly become a standard for investigating white matters disorders,
as Diffusion Tensor Imaging (DTI) can reveal abnormalities in Saclay, France Denis Le Bihan
vii
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Preface
I n 1994, I was working as a Medical Physicist in Leicester Royal on the team; it is inevitable that I have not been able to include
Infi rmary in the UK, on a national medical physics training all the star players in the fi eld. However, you know who you are,
scheme in radiotherapy and nuclear medicine. There I met Mark and we know who you are, and I thank you for your understand-
Horsfi eld—the only MR physicist in the department, who said ing about this.
“Del—if you ever fancy doing a PhD, come and see me. There’s
this new thing that’s just been published called diffusion tensor
About the Contents
imaging.” At the time, Peter Basser and colleagues had just pub-
lished their fi rst full papers on estimating and imaging the diffu- The book starts and ends with history. It opens with a historical
sion tensor (following the presentation at the ISMRM in Berlin in overview of the developments in the study of white matter—way
1992). I accepted Mark’s invitation (thanks Mark!), and set about before diffusion MRI—to put diffusion MRI into context. We
trying to understand diffusion MRI. cannot capture the thoughts of those that pioneered these early
As The Faces (or was it Rod Stewart?) sang, “I wish that I works, but we can capture the thoughts of those who have pio-
knew what I know now, when I was younger” (more specifi cally, neered important aspects of diffusion MRI. The book therefore
at the start of my PhD). What I wanted was a “Big Book” contain- closes with personal accounts from six scientists who champi-
ing a graduate course in diffusion MRI. Denis Le Bihan’s book oned the fi eld into what it is today. I am absolutely thrilled to
Diffusion/Perfusion MRI (Raven Press, 1995) was very helpful, include personal accounts from Ed Stejskal and John Tanner, Paul
but it predated many important developments in the early days of Callaghan, Denis Le Bihan, Mike Moseley, and Peter Basser.
DT-MRI. Moreover, fi fteen years have passed since Denis’ book I n between, the book is broadly divided into two halves. The
was written and the fi eld has changed a lot since then. It also fi rst half details mainly theoretical and technical developments in
seems that there is increasing demand for a comprehensive trea- diffusion MRI, while the second half deals predominantly with
tise on diffusion MRI from the basic science and clinical imaging applications in vivo. In terms of selecting disease states, it would
community. be impossible to cover all diseases to which diffusion MRI has
So, the book you are holding in your hands is my humble been applied. My selection therefore aims to capture different
attempt to produce “The Big Book” that serves as a graduate challenges to the technique, or to highlight cases where diffu-
course in diffusion MRI. My hope is that the newcomer to the sion MRI has made a real difference in the clinical or clinical–
fi eld will fi nd at least half of the answers to his or her questions research domain.
between the pages of this book. I also hope that the level of detail Throughout the book, there is a strong bias toward imaging
provided will provide a suffi ciently fi rm grounding as to enable of the white matter. I don’t apologize for this. I may be refl ecting
and inspire entirely new avenues to be explored. At the very least, personal biases, but it occurs to me that the strongest motivator
there should be inspiration for a few dozen PhD projects here! pushing the technological envelope is gaining increased preci-
sion and accuracy of quantifying aspects of neural tissue in vivo.
Consequently, I am absolutely sure that I haven’t covered every-
About the Authors
thing that it is important to know about diffusion MRI. You may,
When Oxford University Press invited me to take on this project, of course, consider there to be some striking omissions, but you
I was fi rst asked to submit a proposal for the book, which was can’t please all of the people all of the time.
to be sent out for review. I sat with a blank piece of paper, and
sketched out a long list of topics that I felt should be included
Expression of Thanks
(see the index at the back of the book). I am a great believer in the
saying “Every man to his own trade.” In other words, I thought I would like to conclude this preface with some words of thanks:
that a book like this should not be written by a single author but The Authors: First and foremost, I would like to thank the
that each topic should be covered by an expert—a person who had authors who have contributed to this book. I feel extremely privi-
pioneered, developed, or led the fi eld. So, I sat about sketching leged to have worked with this dream team, to have chatted with
out a hypothetical “dream team” of star players (from which the them at conferences, and to call many of them a friend. These
Editor excludes himself) as the authors. I was clearly delighted folks have been extremely patient with me when I sent back a
when I got 100 % acceptance from all the invitations, and so, you chapter for the fourth or fi fth revision. This gang of 50 or more
hold the product of the efforts of a substantial dream team. Of authors has battled through some personal challenges in order for
course, like any dream team, there can only be so many players the book to see fruition. Over the course of the book’s preparation,
ix
