Acoustical Imaging – serie

The International Symposium of Acoustical Imaging has been widely recognized as a main forum for presentations of advanced research results in both theoretical and experimental development. Held regularly since 1968, the symposium brings together international leading researchers in the area of acoustical imaging. The proceedings from the 24th meeting contain articles on the following topics: advanced systems and techniques, microscopy and non-destructive evaluation, and biomedical applications.

This book constitutes the Proceedings of the 26th Symposium on Acoustical Imaging held inWindsor, Ontario, Canada during September 9-12, 2001. This traditional scientific event is recognized as a premier forum for the presentation of advanced research results in both theoretical and experimental development. The lAIS was conceived at a 1967Acoustical Holography meeting in the USA. Since then, these traditional symposia provide an opportunity for specialists who are working in this area to make new acquaintances, renew old friendships and present recent results of their research. Our Symposium has grown significantly in size due to a broad interest in various topics and to the quality of the presentations. For the firsttime in 40 years, the IAIS was held in the province of Ontario in Windsor, Canada's Automotive Capital and City of Roses. The 26th IAIS attracted over 100specialists from 13countries representing this interdisciplinary field in physical acoustics, image processing, applied mathematics, solid-state physics, biology and medicine, industrial applications and quality control technologies. The 26th lAIS was organized in the traditional way with only one addition-a Special Session "History of Acoustical Imaging" with the involvement of such well known scientists as Andrew Briggs, Noriyoshi Chubachi, Robert Green Jr., Joie Jones, Kenneth Erikson, and Bernhard Tittmann. Many of these speakers are well known scientists in their fields and we would like to thank them for making this session extremely successful.

Acoustical imaging has become an indispensable tool in a variety of fields. Since its introduction, the applications have grown and cover a variety of techniques, producing significant results in fields as disparate as medicine and seismology. Cutting-edge trends continue to be discussed worldwide.This book contains the proceedings of the 27th International Symposium on Acoustical Imaging (AI27), which took place in Saarbrücken, Germany, from March 24th to March 27th 2003. The Symposium belongs to a conference series in existence since 1968. AI27 comprised sessions on: Medical Imaging, Non-Destructive Testing, Seismic Imaging, Physics and Mathematics of Acoustical Imaging, Acoustic Microscopy. During two well-attended workshops the applications of quantitative acoustical imaging in biology and medical applications, and in near-field imaging of materials, were discussed. Based on its cross-disciplinary aspects, the authors of the papers of AI27 present experiments, theory and construction of new instruments.

The International Acoustical Imaging Symposium has been held continuously since 1968 as a unique forum for advanced research in all areas of acoustical imaging. The interdisciplinary nature of the Symposium and the wide international participation are two of its main strengths. Scientists from around the world present papers in all fields of acoustical imaging in an informal environment conducive to lively discussion and cross-fertilization. Acoustical Imaging remains the unique Symposium in the world that promotes the sharing of technology, developments, methods and theory among all areas of acoustics. The fact that a loyal community of scientists has supported this Series since 1968 is evidence of its impact on the field. The Symposium Series continues to thrive in a busy calendar of scientific meetings without the infrastructure of a professional society. It does so because those who attend and those who rely on the Proceedings as a we- known reference work acknowledge its value. The 28th International Acoustical Imaging Symposium was held in San Diego, California USA during March 20–23, 2005. Volume 28 of the Proceedings contains an excellent collection of papers presented in six major categories: • Acoustic Microscopy • Components and Systems • Computed Tomography • Biological and Medical Applications • Non-Destructive Evaluation • Physics and Mathematics xv xvi Preface

The 29th International Symposium on Acoustical Imaging was held in Shonan Village, Kanagawa, Japan, April 15-18, 2007. This interdisciplinary Symposium has been taking place every two years since 1968 and forms a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. In the course of the years the volumes in the Acoustical Imaging Series have developed and become well-known and appreciated reference works.Offering both a broad perspective on the state-of-the-art in the field as well as an in-depth look at its leading edge research, this Volume 29 in the Series contains again an excellent collection of seventy papers presented in nine major categories: (1) Strain Imaging, (2) Biological and Medical Applications, (3) Acoustic Microscopy, (4) Non-Destructive Evaluation and Industrial Applications, (5) Components and Systems, (6) Geophysics and Underwater Imaging, (7) Physics and Mathematics, (8) Medical Image Analysis, (9) FDTD method and Other Numerical Simulations.

This book contains the technical papers presented at the 16th International Symposium on Acoustical Imaging which was held in Chicago, Illinois USA from June 10-12, 1987. This meeting has long been a leading forum for acoustic imaging scientists and engineers to meet and exchange ideas from a wide range of disciplines. As evidenced by the diversity of topical groups into which the papers are organized, participants at the meeting and readers of this volume can benefit from developments in medical imaging, materials testing, mathematics, microsocopy and seismic exploration. A common denominator in this field, as its name implies, is the generation, display, manipulation and analysis of images made with mechanical wave energy. Sound waves respond to the elastic properties of the medium through which they propagate, and as such, are capable of characterizing that medium; something that cannot be done by other means. It is astonishing to realize that acoustic wave imaging is commonly performed over about eight decades of frequency, with seismology and microscopy serving as lower and upper bounds, respectively. The physics is the same, but the implementations are quite different and there is much to learn. The conference chairman and editor wishes to express his appreciation to those who helped run the symposium - namely the Technical Review COIIII1ttee and Session Cbair:aen including Floyd Dunn, Gordon S.

The 17th International Symposium on Acoustical Imaging was held at Tohoku University, Sendai, Japan, during May 31-June 2, 1988. The symposium was organized by the ultrasonics research group of Tohoku University and the IEEE ijFFC Society, Tokyo Chapter. Of the 128 papers submitted, 88 were presented during the symposium, which comprised 144 researchers from 13 countries. This volume contains 81 papers as the record of the symposium and is clas­ sified into the following sections: (1) Acoustic Microscopy and its Applications; (2) Non-Destructive Evaluation; (3) Signal Processing of Images; (4) Acoustic Measurements and Physical Acoustics; (5) Medical Ultrasonic Diagnostics; (6) Acoustic Sensors; (7) Acoustic Holography and Tomography; (8) Seismic Exploration; and (9) Imaging Instrumentation and Other Techniques. A number of the papers submitted were associated with medical ultrasonic diagnostics and acoustic microscopy, reflecting a major activity in acousti­ cal imaging at Tohoku University. Accordingly, two invited talks were focused on this area: acoustic microscopy by Dr. G. A. D. Briggs of the University of Oxford and medical ultrasonics by Prof. M. Tanaka of Tohoku University. In light of the history of research in this field at our university, we are delighted to have had the opportunity to host the 17th symposium.

This volume constitutes the proceedings of the Thirteenth Inter­ national Symposium on Acoustical Imaging which was held in Minneapolis, Minnesota during October 26-28, 1983. Forty-eight research papers were presented during the meeting by researchers from twelve countries, again demonstrating the true international character of these meetings. Of these presentations this volume contains forty-two complete manuscripts. The abstracts for addi­ tional papers that were not available at publication time are also included. According to the recent tradition of these symposia an inter­ disciplinary program under the general theme of acoustical imaging was organized. This can clearly be observed from the wide range of topics and approaches contained in the following manuscripts. There are papers of mathematical nature dealing with the basis of image formation and algorithms for digitally carrying out specific imaging tasks. One finds manuscripts dealing with the design and construction of imaging transducers as well as complete imaging systems. Applications include medical imaging and nondestructive testing, seismic and underwater imaging. This volume, therefore, should be of interest to active researchers in acoustical imaging as a report on current research and to workers in signal process­ ing, sonics and ultrasonics who are interested in exploring the diverse areas of application for their fields of interest. These proceedings are organized in seven topical sections, paral­ leling the sessions of the conference. These are: Inversion and Tomography, Microscopy, Scattering and Propagation, Tissue and Material Characterization, Signal Processing, Transducers and Arrays, Imaging Systems and Special Techniques.

This volume contains the Proceedings of the Eighth International Symposium on Acoustical Imaging, held in Key Biscayne, Miami, Florida May 29th to June 2nd, 1978. The title of the Symposium was changed again this year by dropping the word "Holography" to reflect the further emphasis on the general imaging aspects of the Symposium and the de-emphasis on the Holographic aspects. Because of this continued changing nature of the Symposium Series this volume has undergone the title change from ACOUSTICAL HOLOGRAPHY to ACOUSTICAL IMAGING. The 47 papers presented here illustrate the continued growth in this dynamic field. There has been a large emphasis on Array Technology as well as Underwater Applications, Seismic Applications, Transducers, New Methods, Acoustic Microscopy, Non-destructive Testing, Computer Tomography Techniques, Medical Applications as well as Tissue Characterization. The meeting was a great success and a stimulating experience for all concerned due principally to the enthusiasm and contrib­ utions of all of the authors represented here. The editor wishes to extend his appreciation and thanks to each and everyone of them. The editor also wishes to thank the members of the Program Committee who helped in selecting the papers and giving their able advice on the details of the meeting. The Program Committee con­ sisted of Pierre Alais, University of Paris, Byron B. Brendon, Holosonics, Inc. , C. B. Burckhardt, Hoffman-LaRoche and Co. , Basle, Switzerland, Philip S. Green, Stanford Research Institute, Menlo Park, California, B. P.

The contents of this volume are the proceedings of the 23'd International Symposium on Acoustical Imaging which took place 13-16 April, 1997, in Boston, Massachusetts. The first Symposium met 25 years ago. Originally the Symposium met in California, then elsewhere within the United States but beginning in 1988 the Symposia began to meet outside of the United States as welL It is now being held about every eighteen months, alternately in the United States and then outside. The present pattern is to hold one meeting in East Asia, then in the USA, then in Europe and again in the USA However, for scheduling reasons the next Symposium will be in Santa Barbara, California, followed by England and then East Asia. It is to be noted that the Symposium is a free standing institution, not associated with any other organization. Each meeting is the total responsibility of its chairman with the advice of past chairmen. Papers are submitted in response to the call for them and reviewed by an International Scientific Advisory Board . . The quality depends entirely on the response to the calL It is gratifYing to note that the Symposium has attained the status that attracts high quality contributions despite (or perhaps because ot) the loose structure. Two factors that have appeal are that there is only one session and that there is time during the meeting for extensive discussion.

This book constitutes the Proceedings of the 26th Symposium on Acoustical Imaging held inWindsor, Ontario, Canada during September 9-12, 2001. This traditional scientific event is recognized as a premier forum for the presentation of advanced research results in both theoretical and experimental development. The lAIS was conceived at a 1967Acoustical Holography meeting in the USA. Since then, these traditional symposia provide an opportunity for specialists who are working in this area to make new acquaintances, renew old friendships and present recent results of their research. Our Symposium has grown significantly in size due to a broad interest in various topics and to the quality of the presentations. For the firsttime in 40 years, the IAIS was held in the province of Ontario in Windsor, Canada's Automotive Capital and City of Roses. The 26th IAIS attracted over 100specialists from 13countries representing this interdisciplinary field in physical acoustics, image processing, applied mathematics, solid-state physics, biology and medicine, industrial applications and quality control technologies. The 26th lAIS was organized in the traditional way with only one addition-a Special Session "History of Acoustical Imaging" with the involvement of such well known scientists as Andrew Briggs, Noriyoshi Chubachi, Robert Green Jr., Joie Jones, Kenneth Erikson, and Bernhard Tittmann. Many of these speakers are well known scientists in their fields and we would like to thank them for making this session extremely successful.

This volume contains 131 of the papers presented at the 22nd International Symposium on Acoustical Imaging. This meeting, which was held for the first time in Florence, Italy, on September 3-6, 1995, allowed an intense and friendly exchange of ideas between over 150 researchers from 26 different countries of Europe (70%), America (20%), Asia and Australia (10%). The Symposium started on Sunday, September 3, with the opening Session held in the magnificent 'Salone dei 500' in Palazzo Vecchio; this included invited talks by Peter WeHs and Hua Lee, who reviewed the State of the Art in Acoustical Imaging research. One hundred and forty papers, selected from the nearly 200 submitted Abstracts, were presented in 11 non-parallel oral Sessions and one Poster Session. This year a 'Best Poster' award was introduced, which was won by V.Miette, M.Fink and F.Wu. Also, a special session on Acoustical Microscopy was organized by Walter Arnold, in which invited speakers Ioie Iones, Oleg Kolosov, Andrew Briggs and Ute Rabe reviewed the capabilities of this em erging topic.

This volume represents the proceedings of the 21 st International Symposium on Acoustical Imaging, which was held at the Surf and Sand Hotel in Laguna Beach, California, March 28-30, 1994. These unique and highly interdisciplinary series of symposiums have met at intervals of roughly 18 months over the past 30 some years. In general these meetings are devoted to all aspects and all fields of imaging that use acoustics. The meetings are usually small, with 100 to 200 participants, and stimulate useful interchanges across disciplines. These are the only regular meetings where the major researchers in all areas of acoustical imaging can come together to interchange ideas and new concepts. The Acoustical Imaging Symposiums have long been regarded as the premier meeting of this type in the general field of acoustics. The highly regarded and carefully edited proceedings have been published regularly by Plenum Press. I am proud and honored to serve as editor of the 21st volume in this series. The 21st Symposium was attended by well over 100 participants from some 18 countries. During the three day symposium, 94 scientific presentations were given, 66 as formal lectures and 28 in a poster format. Sufficient time was available during the conference, both following the presentations and informally during meals and breaks, for active discussions among all participants. Over 80 of the presentations have been selected for inclusion in these proceedings.

The 105 theses contained in this book are selected from those whose authors were present at the 20th International Symposium on Acoustical Imaging. held at Southeast University. Nanjing. China. during September 12-14. 1992. It was the first time that the symposium had been held in China. Our efforts to host the conference goes back to the 15th International Symposium on Acoustical Imaging held in Halifax. Canada. in 1986. We are glad that the 20th symposium has been successfully held at last. We are ardent for the symposium not only because we attach much importance to the field of acoustical imaging. but also because we admire the tradition of the serious academic exploration and friendly cooperation of the scholars attending the symposium. The theses in this book are from 21 countries and those by Mr. G. Wade. Takuso Sato. J. F. Greenleaf. K. J. Langenberg. and Wencai Yang are the specially invited papers. These theses cover such important fields of acoustical imaging as follows: 1. Mathematics and physics of acoustical imaging; 2. Components and industry application; 3. Applications in medicine and biology; 4. Applications in nondestructive testing; 5. Applications in geophysics; 6. Underwater acoustical imaging. All these theses reflect the latest progress in theory and technology. We are very grateful to all the authors who have provided these theses.

This book constitutes the proceedings of the 19th International Symposium on Acoustical Imaging at the Ruhr-University Bochum, Germany during April 3 -5, 1991. It was the first time that the symposium was held in Europe after major political changes happened in that area. The freedom to travel for all people from eastern European countries was an obvious reason for the great numbers of sub­ mitted abstracts and for numerous conference participants. 193 of 239 submitted contributions from 29 countries were accepted for presentation by authors from USA (13%), Canada (2%), Japan (7%), Peoples Republic of China (7%), United Kingdom (4%), France (7%), Italy (3%), Poland (4%), Soviet Union (7%), Germany (28%) and other countries (18%). 283 scientists from 29 countries attended the conference representing the interdisciplinary field between mathematics, physics, engineering and medicine. 151 papers were available for publication in this proceedings covering the topics 1. Mathematics and Physics of Acoustical Imaging 2. Components and Systems 3. Applications in Medicine and Biology 4. Applications in Nondestructive Testing 5. Remote Sensing Applications 6. Industrial Applications A relative large number of contributions on acoustical microscopy was included in the conference program within topics 3 and 4. Also, papers on "non-traditional" acoustical imaging subjects, e. g. on phonon imaging and on remote sensing in the atmosphere, have broadened the scope of the conference. The success and stimulation of the conference and of the papers presented in this volume is owed, of course to the authors and participants.

How to produce images with sound has intrigued engineers and scientists for many years. Bats, whales and dolphins can easily get good mental images with acoustical energy, but humans have little natural ability for obtaining such images. The history of engineering and science, however, is an impressive demonstration that technological solutions can compensate, and then some, for deficiencies of nature in humans. Thus with the proper technology, we too can "see" with sound. Many methods involv­ ing ultrasonic energy can be employed to enable us to do so. Few of these methods are at all reminiscent of the acoustic systems employed by animals. Pulse-echo, phase-amplitude and amplitude-mapping approaches constitute the conceptual bases for three fundamentally different types of acoustic imaging systems and can be used for categorizing the systems. However, by now systems exist that combine the approaches in such sophisticated ways as to make an unambiguous categorization of some of the more complicated systems difficult or impossible. Among the instruments so far pro­ duced are mechanically-scanning focused instruments, chirped pulse-echo instruments, and instruments involving holography, tomography, parametric excitation, phase conju­ gation, neural networks, random phase transduction, finite element methods, Doppler frequency shifting, pseudo inversion, Bragg diffraction and reflection, and a host of other principles. The fifty-five chapters in this volume are selected from papers presented at the Eighteenth International Symposium on Acoustical Imaging which was held in Santa Barbara, California on September 18 - 20, 1989.

The formation of images by ultrasound is a fascinating study, with well-established, yet rapidly growing, applic­ ations in medicine and with increasing relevance to a surprisingly disparate set of problems in the non-destructive examination of materials and components. The present volume is a record of the research presented at the Twelfth International Symposium on Acoustic Imaging, held in London during July 1982. Whilst, therefore, it offers primarily a snap-shot in time of a rapidly developing field, it is so organized that it will also serve as a high-speed entry into the literature for someone embarking, for the first time, on· researches in this branch of applied science. As in previous volumes, some of the work reported is concerned with topics which, whilst of critical importance to the performance of any imaging system, - e.g. transducers, signal processing may not address themselves to image formation per se. A new departure is the inclusion of photo-acoustic imaging a subject of rapidly growing importance for many of the same application areas relevant to acoustical imaging.

This volume contains forty-one papers presented at the Eleventh International Symposium on Acoustical Imaging held on 4-7 Ma~ in Monterey, California. The objective of this conference series is to bring together workers in diverse areas and applications of Acoustical Imaging for interaction and exchange of ideas. People working in other aspects of scalar wave theory and applications also benefit from this series. The papers presented here demonstrate continued growth in the activity of this field. In this conference there was emphasis on New Techniques, Acoustic Tomography, Tissue Characterization, Signal Processing, Inversion Techniques, and Transducers and Arrays. The success and stimulation of the conference and of the papers presented in this volume is owed, of course to the authors and participants. Many thanks are due to the authors and their co-workers for their diligence and enthusiasm in performing their research, preparing their manuscripts and presenting their results. The editor would like to express his appreciation to each and every one of them.

This volume contains forty-six of the papers presented at the Ninth International Symposium on Acoustical Imaging held December 3-6, 1979, in Houston, Texas. The theme of the confer- ence was the integration of applications technology. The major objective of the conference was to promote interaction among researchers working on different applications of acoustical imaging. In addition to serving as a state-of-the-art research ref- erence, this volume includes six tutorial review papers. For convenience, all the papers are grouped under the following headings: methods, transducers, processing and display, phased array considerations, acoustic microscopy/non-destructive evalu- ation, reconstructive tomography and inversion techniques, tissue characterization and impediography, nedica1 applications, under- water applications, and seismic applications. The editor would like to thank the authors and the confer- ence participants. The editor would also like to express his appreciation for the assistance in evaluating the abstracts from the following members of the Program Committee: Mahfuz Ahmed, University of California Irvine l:1edica1 Center; Pierre A1ais, Paris University, France; C.B. Burckhardt, Hoffman-Laroche, Basel, Switzerland; B. P. Hildebrand, Spectron Development Labora- tories, Inc. , Costa Mesa, California; Larry W. Kessler, Sonoscan, Inc. , Bensenville, Illinois; Rolf Uue11er, University of Hinnesota, l1inneapo1is, Uinnesota; John P. Powers, Naval Post Graduate School, J:1onterey, California; Jerry L. Sutton, Naval Ocean Systems Center, San Diego, California; F. L. Thurstone, Duke University, Durham, North Carolina; Robert C. Waag, University of Rochester, Rochester, New York; and Glen Wade, University of California, Santa Barbara, California.

This volume contains the proceedings of the Tenth International Symposium on Acoustical Imaging held in Cannes, France, October 12th through the 16th, 1980. Fifty-seven papers were presented over the course of the four day meeting. Fifty-two manuscripts were received in time for publication of the proceedings. There was representation from 14 nations, including England, France, U.S.A., West Germany, Canada, Italy, Japan, Poland, The Netherlands and Norway among the authors and in addition, Switzerland, Spain, Belgium, and Denmark were represented. The following papers were presented at the meeting for which manuscripts were not received in time for publication: "Improved Phased Array Imaging and Medical Diagnosis" by F.L. Thurstone; "Scanning Acoustic Microscope Operating in the Reflection Mode" by H. Kanda, I. Ishikawa, T. Kondo, and K. Katakura; "Empirical Determination of Flaw Characteristics Using the Scanning Laser Acoustic Microscope - SLAM" by D. Yuhes, C.L. Forres, and L.W. Kessler; "A Wide Angled Fraction Limited Holographic Lens System for Acoustical Imaging" by H. Heier; "Progress in the Development of Sonographic Contrast Agents" by J. Ophir, and F. Maklad, A. Gobuty and R.E. McWhirt.

Volume 15 follows the format of earlier volumes in the series. The contents give the next installment in the varied aspects of acoustical imaging research. On this occasion, some emphasis was placed on the rela­ tionship of l1nderwater acoustics to acoustical imaging and a volume of papers under the title "Underwater Acoustics Proceedings from the 12th ICA Symposium held in Halifax," will appear at roughly the same time as this volume. There is no duplication in these volumes but they are in­ terlinked, at least to the extent that papers from common conference sessions appear in one or another volume. An innovation is the review paper presented at the beginning of the volume "A History of Acoustical Imaging," by G Wade. This fairly detailed review comes at a point in time when so much has been achieved and in some cases passed by, that a record of some of the earlier work might help to keep a balance with the large collections of research papers which have appeared in the many volumes.

The International Symposium of Acoustical Imaging has been widely recognized as the premier forum for presentations of advanced research results in both theoretical and experimental development. Held regularly since 1968, the symposium brings together th leading international researchers in the area of acoustical imaging. The 24 meeting is the third time Santa Barbara hosted this international conference and it is the first time the meeting was held on the campus of the University of California, Santa Barbara. As many regular participants noticed over the years, this symposium has grown significantly in size due to the quality of the presentations as well as the organization itself. A few years ago multiple and poster sessions were introduced in order to accommodate this growth. In addition, the length of the presentations was shortened so more papers could be included in the sessions. During recent meetings there were discussions regarding the possibility of returning to the wonderful years when the symposium was organized in one single session with sufficient time to allow for in-depth presentation as well as discussions of each paper. And the size of the meeting was small enough that people were able to engage in serious technical interactions and all attendees would fit into one photograph. In light of the constraints of the limited budget with respect to the escalating costs it was not considered feasible.

In the course of the years the volumes in the Acoustical Imaging Series have developed to become well-known and appreciated reference works. Offering both a broad perspective on the state of the art in the field as well as an in-depth look at its leading edge research, this Volume 30 in the Series contains again an excellent collection of contributions, presented in five major categories:

Acoustical imaging has become an indispensable tool in a variety of fields. Since its introduction, the applications have grown and cover a variety of techniques, producing significant results in fields as disparate as medicine and seismology. Cutting-edge trends continue to be discussed worldwide.This book contains the proceedings of the 27th International Symposium on Acoustical Imaging (AI27), which took place in Saarbrücken, Germany, from March 24th to March 27th 2003. The Symposium belongs to a conference series in existence since 1968. AI27 comprised sessions on: Medical Imaging, Non-Destructive Testing, Seismic Imaging, Physics and Mathematics of Acoustical Imaging, Acoustic Microscopy. During two well-attended workshops the applications of quantitative acoustical imaging in biology and medical applications, and in near-field imaging of materials, were discussed. Based on its cross-disciplinary aspects, the authors of the papers of AI27 present experiments, theory and construction of new instruments.

The International Acoustical Imaging Symposium has been held continuously since 1968 as a unique forum for advanced research in all areas of acoustical imaging. The interdisciplinary nature of the Symposium and the wide international participation are two of its main strengths. Scientists from around the world present papers in all fields of acoustical imaging in an informal environment conducive to lively discussion and cross-fertilization. Acoustical Imaging remains the unique Symposium in the world that promotes the sharing of technology, developments, methods and theory among all areas of acoustics. The fact that a loyal community of scientists has supported this Series since 1968 is evidence of its impact on the field. The Symposium Series continues to thrive in a busy calendar of scientific meetings without the infrastructure of a professional society. It does so because those who attend and those who rely on the Proceedings as a we- known reference work acknowledge its value. The 28th International Acoustical Imaging Symposium was held in San Diego, California USA during March 20–23, 2005. Volume 28 of the Proceedings contains an excellent collection of papers presented in six major categories: • Acoustic Microscopy • Components and Systems • Computed Tomography • Biological and Medical Applications • Non-Destructive Evaluation • Physics and Mathematics xv xvi Preface

The International Symposium on Acoustical Imaging is a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. This interdisciplinary Symposium has been taking place continuously since 1968. In the course of the years the proceedings volumes in the Acoustical Imaging Series have become a reference for cutting-edge research in the field. In 2011 the 31st International Symposium on Acoustical Imaging was held in Warsaw, Poland, April 10-13. Offering both a broad perspective on the state-of-the-art as well as  in-depth research contributions by the specialists in the field, this Volume 31 in the Series contains an excellent collection of papers in six major categories: Biological and Medical ImagingPhysics and Mathematics of Acoustical ImagingAcoustic MicroscopyTransducers and ArraysNondestructive Evaluation and Industrial ApplicationsUnderwater Imaging

In the course of the years the volumes in the Acoustical Imaging Series have developed to become well-known and appreciated reference works. Offering both a broad perspective on the state of the art in the field as well as an in-depth look at its leading edge research, this Volume 30 in the Series contains again an excellent collection of contributions, presented in five major categories:

The 29th International Symposium on Acoustical Imaging was held in Shonan Village, Kanagawa, Japan, April 15-18, 2007. This interdisciplinary Symposium has been taking place every two years since 1968 and forms a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. In the course of the years the volumes in the Acoustical Imaging Series have developed and become well-known and appreciated reference works.Offering both a broad perspective on the state-of-the-art in the field as well as an in-depth look at its leading edge research, this Volume 29 in the Series contains again an excellent collection of seventy papers presented in nine major categories: (1) Strain Imaging, (2) Biological and Medical Applications, (3) Acoustic Microscopy, (4) Non-Destructive Evaluation and Industrial Applications, (5) Components and Systems, (6) Geophysics and Underwater Imaging, (7) Physics and Mathematics, (8) Medical Image Analysis, (9) FDTD method and Other Numerical Simulations.