Table Of ContentQUANTITATIVE METHODS IN BONE DENSITOMETRY
QUANTITATIVE METHODS IN
BONE DENSITOMETRY
ALAN L. HUDDLESTON, PH.D.
Chief, Medical Physics
Baylor University Medical Center
Charles A. Sammons Cancer Center
Division of Radiation Oncology
Dallas, Texas 75246
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KLUWER ACADEMIC PUBLISHERS
BOSTON/DORDRECHT/LONDON
© 1988 by Kluwer Academic Publishers, Boston.
Softcover reprint of the hardcover 15t edition 1988
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Library of Congress Cataloging-in-Publication Data
Huddleston, Alan.
Quantitative methods in bone densitometry.
Includes index.
1. Osteoporosis - Diagnosis. 2. Bone densitometry.
1. Title. [DNLM: 1. Bone and Bones - radiography.
2. Densitometry - methods. 3. Osteoporosis - radiography.
4. Tomography, X-Ray Computed-methods. WE 200 H884q]
RC931.073H831988 616.7'10754 87-35241
ISBN-13: 978-1-4612-8971-5 e-ISBN-13: 978-1-4613-1725-8
DOl: 10.1007/978-1-4613-1725-8
To the memory of my brother, Gary Lee Huddleston, M.D.
CONTENTS
Preface and Acknowledgments
Xl
1 Introduction 1
Composition of Bone Tissue 4
Bone Strength and Bone Mass 6
Bone Mass Measurements 7
2 Radiographic Film Methods 13
Radiographic Diagnosis (Radioscopy) 14
Trabecular Indices 15
Principles of Radiogram met ry 18
Combined Cortical Thickness 19
Barnett-Nordin Index 19
Cortical Area 19
Percent Cortical Area 20
Exton-Smith Index 20
Principles of Metacarpal Measurements 20
Magnification Techniques 22
Vertebral Measurements 23
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Radius Measurements 23
Precision and Accuracy (Radiogrammetry) 25
Clinical Measurements 26
Radiographic Photodensitometry 28
Precision and Accuracy (Photodensitometry) 31
Videodensitometry 31
3 Single-Photon Absorptiometry 33
Principles of Measurement 34
X-ray Tube Sources for SPA 39
Multiwire Proportional Counters 40
Two-Dimensional SPA 42
Precision and Accuracy (SPA) 43
Effects of Adipose Tissue 45
Clinical Measurements 46
SPAin Children 51
Fracture Risk 54
Radiation Dose to Patients 54
4 Dual-Photon Absorptiometry 57
Principles of Measurement 57
Instrumentation and System Design 60
Beam Hardening and Crossover Corrections 68
Correction for Fat 70
Precision and Accuracy 71
Total-Body Bone Mineral Measurements 73
Clinical Measurements 79
Fracture Threshold 82
Radiation Dose to Patients 82
5 Quantitative Computed Tomography 85
Monoenergetic (Gamma) CT 86
Precision and Accuracy (Gamma-CT) 88
Single-Energy X-ray Quantitative CT 89
Precision and Accuracy (Single-Energy X-ray CT) 97
Beam-Hardening Effects 101
Partial Volume Effects 104
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Effects of Marrow Fat 105
Dual-Energy X-ray Quantitative CT 106
Precision and Accuracy (Dual-Energy CT) 108
Clinical Measurements 108
Radiation Dose to Patients 110
6 Scattering Methods in Densitometry 113
Compton-Scatter Imaging Methods 114
Fixed-Point Compton-Scatter Methods 125
Dual-Source/Dual-Detector Methods 127
Dual-Source/Single-Detector Methods 133
Single-Source/Single-Detector Methods 134
Single-Source/Dual-Detector Method 139
Finite Geometry Effects 139
Multiple Scattering 140
Clinical Measurements 140
Coherent/Compton-Scatter Methods 144
7 Activation Analysis Methods 161
Principles of Measurement 162
Partial-Body NAA 167
Precision and Accuracy (NAA) 168
Clinical Measurements 170
Radiation Dose to Patients (NAA) 176
Proton Activation Analysis (P AA) 176
Muonic X-ray Excitation 177
8 Clinical Applications and Comparison of Methods 179
References 195
Index 215
PREFACE
Interest in bone densitometry methods has recently experienced a resurgence
within the medical community. Physicians have become more interested than
ever before in the diagnosis and treatment of degenerative diseases of bone
such as osteoporosis. The public perception of osteoporosis and its prevention
has been recently heightened. Because osteoporosis is widespread, especially
in women, and leads to an increase in fractures in our population, many re
searchers and clinicians are strongly motivated in their search for more sensi
tive and accurate methods of diagnosis.
This book was written for physicians, scientists, engineers, medical phy
sicists, and others desiring an introduction or further understanding of this
exciting field. Beginning with the early development of x-ray film methods
for assessing bone status, the field has steadily grown throughout the years.
Novel and interesting devices have been designed for the measurement of bone
mass, bone density, cortical thickness, and other parameters of bone changes.
Both qualitative and quantitative bone methods are described. The techniques
include imaging devices such as CT and radiography as well as fixed point
methods in which bone characteristics of a region of interest are analyzed.
Clinical applications of these bone densitometry methods are included as an
indication of the usefulness of the various techniques, although the complete
analysis of clinical data was not exhaustive nor intended in this work. How
ever, it is intended that an appreciation of the extensive efforts of the many re
searchers who have worked to develop these techniques and an understanding
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of the basic physical principles will be realized by this book. Further develop
ment of the field of bone densitometry will require new insights for the integra
tion of technology and biomedical knowledge. Further investigation of the
methodology is necessary to increase the sensitivity, precision, and accuracy
with which bone parameters may be assessed by noninvasive means in the
human body. It is hope that this work may inspire others to meet this challenge.
ACKNOWLEDGMENTS
Grateful acknowledgment is made for the interest and appreciation expressed
by the many authors of published works in this field. Special thanks are con
veyed to those authors who have granted permission to reproduce or extract
information from their published works and to the publishers of the many
referenced journals and books on the subject. In particular, I would like to
acknowledge Moses A. Greenfield, Ph.D., my mentor and adviser as a gra
duate student, without whose encouragement and enthusiasm this work
would not have been written. Appreciation is expressed for the patience of my
wife, Diane, and my daughters, Lisa and Katherine, and for the encourage
ment of my family and friends.
Alan L. Huddleston
QUANTITATIVE METHODS IN BONE DENSITOMETRY
