DUAL ENERGY X-RAY ABSORPTIOMETRY Edited by Abdellah El Maghraoui Dual Energy X-Ray Absorptiometry Edited by Abdellah El Maghraoui Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2011 InTech All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. As for readers, this license allows users to download, copy and build upon published chapters even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. Notice Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published chapters. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Dejan Grgur Technical Editor Teodora Smiljanic Cover Designer InTech Design Team First published January, 2012 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org Dual Energy X-Ray Absorptiometry, Edited by Abdellah El Maghraoui p. cm. ISBN 978-953-307-877-9 free online editions of InTech Books and Journals can be found at www.intechopen.com Contents Preface IX Part 1 Bone Mineral Density 1 Chapter 1 Interpreting a DXA Scan in Clinical Practice 3 Abdellah El Maghraoui Chapter 2 Monitoring DXA Measurement in Clinical Practice 19 Abdellah El Maghraoui Chapter 3 Bone Loss and Seasonal Variation in Serial DXA Densitometry – A Population-Based Study 29 Joonas Sirola, Toni Rikkonen, Risto Honkanen, Jukka S. Jurvelin, Marjo Tuppurainen and Heikki Kröger Part 2 Body Composition 43 Chapter 4 The Validity of Body Composition Measurement Using Dual Energy X-Ray Absorptiometry for Estimating Resting Energy Expenditure 45 Chiyoko Usui, Motoko Taguchi, Kazuko Ishikawa-Takata and Mitsuru Higuchi Chapter 5 Dxa as a Tool for the Assessment of Morphological Asymmetry in Athletes 59 Magdalena Krzykała Chapter 6 Body Composition in Disabilities of Central Nervous System 75 Yannis Dionyssiotis Part 3 Miscellaneous 95 Chapter 7 Internal Design of the Dry Human Ulna by DXA 97 S. Aguado-Henche, A. Bosch-Martín, P. Spottorno-Rubio and R. Rodríguez-Torres VI Contents Chapter 8 Ex Vivo and In Vivo Assessment of Vertebral Strength and Vertebral Fracture Risk Assessed by Dual Energy X-Ray Absorptiometry 105 Kazuhiro Imai Chapter 9 Dietary Protein and Bone Health 121 Anne Blais, Emilien Rouy and Daniel Tomé Preface Dual-energy x-ray absorptiometry (DXA) is now recognized as the reference method to measure bone mineral density (BMD) with acceptable accuracy errors, good precision and reproducibility. The World Health Organization (WHO) has established DXA as the best densitometric technique for assessing BMD in postmenopausal women and has based the definitions of osteopenia and osteoporosis on its results. DXA allows accurate diagnosis of osteoporosis, estimation of fracture risk and monitoring of patients undergoing treatment. Correct performance of BMD measurements using DXA requires rigorous attention to detail in positioning and analysis. Performing DXA studies incorrectly can lead to major mistakes in diagnosis and therapy. Measurement error must be considered when evaluating serial assessments. A clear understanding of the interpretation of serial measurements and the statistical principles impacting upon their interpretation is necessary to determine whether a change is real and not simply random fluctuation. Moreover, it is important to keep in mind that fracture-protection benefit may be realized before BMD gains are detected. Physicians interested in osteoporosis management, even if not directly involved in the performance and interpretation of DXA, should be familiar with the principles of DXA to minimize serious errors and allow proper use of bone densitometry. Additional features of DXA include measurement of BMD at multiple skeletal sites, vertebral fracture assessment (also called vertebral morphometry) using evaluation of vertebral heights with a special software to determine vertebral body dimensions, body composition assessment including bone mineral content, fat mass and lean soft tissue mass of the whole body and the segments. This book contains reviews and original studies about DXA and many different uses in clinical practice (diagnosis of osteoporosis, monitoring of BMD measurement) and in medical research in several situations (e.g. assessment of morphological asymmetry in athletes, estimation of resting energy expenditure, consequences of dietary protein or disabilities of the central nervous system on BMD and body composition, assessment of vertebral strength and vertebral fracture risk, or study of dry bones such as the ulna). It will certainly help the researchers and/or physicians X Preface using DXA to improve their knowledge of the wide range of potential uses that this technique allows. Prof. A. El Maghraoui Rheumatology Department, Military Hospital Mohammed V, Rabat, Morocco [...]... J Theodorou (2002) "Dual- energy X-ray absorptiometry in clinical practice: application and interpretation of scans beyond the numbers." Clin Imaging 26(1): 43-9 Tothill, P and A Avenell (1994) "Errors in dual- energy X-ray absorptiometry of the lumbar spine owing to fat distribution and soft tissue thickness during weight change." Br J Radiol 67(793): 71-5 18 Dual Energy X-Ray Absorptiometry Watts,... treatment of osteoporosis." Postgrad Med J 83(982): 509-517 Blank, R D., D G Malone, et al (2006) "Patient variables impact lumbar spine dual energy X-ray absorptiometry precision." Osteoporos Int 17(5): 768-74 Bolotin, H H (2001) "Inaccuracies inherent in dual- energy X-ray absorptiometry in vivo bone mineral densitometry may flaw osteopenic/osteoporotic interpretations and mislead assessment of antiresorptive... "Discriminative ability of dual- energy X-ray absorptiometry site selection in identifying patients with osteoporotic fractures." Bone 40(4): 1060-5 Baddoura, R., H Awada, et al (2006) "An audit of bone densitometry practice with reference to ISCD, IOF and NOF guidelines." Osteoporos Int 17(7): 1111-5 Baim, S., C R Wilson, et al (2005) "Precision assessment and radiation safety for dualenergy X-ray absorptiometry: ... routine spine x-ray( Duboeuf, Bauer et al 2005; Jacobs-Kosmin, Sandorfi et al 2005; Chapurlat, Duboeuf et al 2006; Damiano, Kolta et al 2006) Fig 4 Vertebral fracture assessment from a dual x-ray absorptiometry image of the spine At this time, DXA devices are not generally accepted as a surrogate for spinal X-rays, though they may provide a useful screening tool in higher-risk patients when spinal X-rays are... weight change." Br J Radiol 67(793): 71-5 18 Dual Energy X-Ray Absorptiometry Watts, N B (2004) "Fundamentals and pitfalls of bone densitometry using dual- energy Xray absorptiometry (DXA)." Osteoporos Int 15(11): 847-54 Woodson, G (2000) "Dual X-ray absorptiometry T-score concordance and discordance between the hip and spine measurement sites." J Clin Densitom 3(4): 319-24 2 Monitoring DXA Measurement... cut-off that can be measured in an individual and is usually considered more useful than the CV in clinical practice (Fuleihan, Testa et al 1995; Ravaud, Reny et al 1999) 20 Dual Energy X-Ray Absorptiometry 2 Methods of bone mineral density reproducibility measurement Precision errors are evaluated by performing repeated scans on a representative set of individuals to characterize the reproducibility... 16(5): 456-9, discussion 579-80 Khan, A A., D A Hanley, et al (2006) "Standards for performing DXA in individuals with secondary causes of osteoporosis." J Clin Densitom 9(1): 47-57 Kuiper, J W., C van Kuijk, et al (1996) "Accuracy and the influence of marrow fat on quantitative CT and dual- energy X-ray absorptiometry measurements of the femoral neck in vitro." Osteoporos Int 6(1): 25-30 Lee, D C., T A L... screening tool in higher-risk patients when spinal X-rays are unavailable For example, individuals over 65, subjects reporting significant height loss or patients on long term glucocorticoid therapy who have not had previous vertebral fractures or spinal radiographs could benefit from a VFA 12 Dual Energy X-Ray Absorptiometry 7 Concordance between measurement sites It is recommended to measure the PA... principles outlined here to minimize serious errors and allow proper use of bone densitometry 9 Abbreviations BMC: bone mineral content BMD: bone mineral density CV: coefficient of variation DXA: dual- energy x-ray absorptiometry IOF: international osteoporosis foundation ISCD: international society for clinical densitometry LSC: least significant change OST: osteoporosis self-assessment tool PE: precision... studies in Asian and White women(Richy, Ethgen et al 2004; El Maghraoui, Guerboub et al 2007; El Maghraoui, Habbassi et al 2007) and men (Adler, Tran et al 2003; Ghazi, Mounach et al 2007) 6 Dual Energy X-Ray Absorptiometry 4 Site of measurement of BMD The ISCD recommends obtaining BMD measurements of the posteroanterior spine and hip(Leib, Binkley et al 2006) The lateral spine and Ward's triangle . DUAL ENERGY X-RAY ABSORPTIOMETRY Edited by Abdellah El Maghraoui Dual Energy X-Ray Absorptiometry Edited by Abdellah El Maghraoui. Composition 43 Chapter 4 The Validity of Body Composition Measurement Using Dual Energy X-Ray Absorptiometry for Estimating Resting Energy Expenditure 45 Chiyoko Usui, Motoko Taguchi, Kazuko Ishikawa-Takata. Bosch-Martín, P. Spottorno-Rubio and R. Rodríguez-Torres VI Contents Chapter 8 Ex Vivo and In Vivo Assessment of Vertebral Strength and Vertebral Fracture Risk Assessed by Dual Energy X-Ray Absorptiometry