'Morphological imaging' and 'functional imaging' are current mainstays for the diagnosis, successful treatment and accurate follow-up of patients with endocrine disorders. Functional and Morphological Imaging of the Endocrine System provides the reader with comprehensive but concise insights in the application of cutting edge imaging techniques and updated imaging protocols for the diagnosis and treatment of hypersecretory hormonal syndromes and functional endocrine masses.

W. F. ARMSTRONG While stress echocardiography is not the first technique to be applied to patients for the diagnosis of coronary artery disease, it represents an impor tant clinical tool, likely to become of increasing pertinence in today's era of cost containment and mandated cost-effectiveness of diagnosis. It may be the most rapidly expanding area of clinical echocardiography today. Stress echocardiography as we know it today represents the natural con clusion and merger of observations made over fifty years ago. In 1935 Tenn ant and Wiggers demonstrated that the immediate result of a coronary oc clusion, was an instantaneous abnormality of wall motion [1]. As viewed from the surface of the heart in an open chest dog preparation, cyanosis and obvious paradoxical bulging of the left ventricular wall was noted. At a similar time Masters and co-workers, using fairly rudimentary exercise de vices, described the response of the human cardiovascular system to sustained exercise (Figure 1) [2]. These two observations diverged for four decades while clinical investigation was pursued along the two parallel lines.

It was only in 1980 that the first recognisable magnetic resonance images of the human brain were published, by Moore and Holland from Nottingham University in England. There then followed a number of clinical trials of brain imaging, the most notable from the Hammersmith Hospital in London using a system designed by EMI, the original manufacturers of the first CT machines. A true revolution in medicine has ensued; in only a few years there are thousands of scanning units, and magnetic resonance imaging (MRI) has assumed a central importance in medical investigation. It is an extraordinary fact that within a few years of development, the esoteric physics of nuclear spin, angular momentum, and magnetic vector precession were harnessed to provide exquisite images of living anatomy; modem science has no greater tribute. That indisputable king of neurology and the oldest of recorded conditions, epilepsy, has not been untouched by the new technology; indeed, it is our view that the introduction of MRI of electroencephalography (EEG) in the late has been as important to epilepsy as was that 1930s. Now, for the first time, the structural and aetiological basis of the condition is susceptible to thorough investigation, and MRI can provide structural detail to parallel the functional detail of EEG. MRI has the same potential as had EEG over 50 years ago, to provide a new level of understanding of the basic mechanisms, the clinical features and the treatment of epilepsy.

The first of a two volume set, Volume 12 provides a long-awaited compilation of NMR theory to paramagnetic molecules. International experts report the latest developments in NMR methodology as applied to strongly relaxed and shifted resonances, detail the theoretical aspects of paramagnetic shift and relaxation, and discuss the interpretive bases of these molecular properties in relation to the structure and function of various paramagnetic molecules.

Scintigraphic imaging with radiolabeled blood elements has continued to be a useful diagnostic modality. The major trust of recent investigation has been in simplifying labeling techniques and developing new agents that will label blood elements selectively in vitro. The VI Symposium of the International Society of Radiolabeled Blood Elements was held in Barcelona (Spain) during November 23 to 27, 1992.The conference was sponsored by the NATO Scientific Affairs Division, the USA Department of Energy and the Spanish National Health Service. This monograph comprises articles that represent most of the 85 papers (70 oral and 15 posters) presented during the symposium. The meeting was attended by 110 investigators hailed from 21 countries. Although lllIn-oxine and 99mTc-HMPAO remain the choice agents for labeling blood components for routine applications, there was heavy emphasis on developing new labeling agents that will either simplify the in vitro labeling procedure, or, even better, will label blood components selectively in vivo, by injecting the radioactive agents directly into patients. The degree of success in imaging target lesions in humans by using these agents has been excellent.

This volume is the scientific chronicle of the NATO Advanced Research Workshop on Computational Aspects of the Study of Biological Macro molecules by Nuclear Magnetic Resonance Spectroscopy, which was held June 3-8, 1990 at Il Ciocco, near Barga, Italy. The use of computers in the study of biological macromolecules by NMR spectroscopy is ubiquitous. The applications are diverse, including data col lection, reduction, and analysis. Furthermore, their use is rapidly evolv ing, driven by the development of new experimental methods in NMR and molecular biology and by phenomenal increases in computational perfor mance available at reasonable cost. Computers no longer merely facilitate, but are now absolutely essential in the study of biological macromolecules by NMR, due to the size and complexity of the data sets that are obtained from modern experiments. The Workshop, and this proceedings volume, provide a snapshot of the uses of computers in the NMR of biomolecules. While by no means exhaustive, the picture that emerges illustrates both the. importance and the diversity of their application."

The basic principles of the phenomenon "erection" have been known since the pioneering work of Kolliker, Eckhard and Langley in the nineteenth century. Nonetheless, under the influence of Freud, erectile dysfunction was predominantly at tributed to psychogenic factors. A more liberal perception of sexuality since the 1960s, the development of new and refined diagnostic techniques, and the expansion of basic research activity resulted in a new concept of erectile dysfunction, identifying arteriogenic, venogenic, endocrinologic or myopathic (cavernous smooth muscle dysfunction) factors. From this research other considerations such as autonomic innervation, cavernous endo thelial intactness or impaired neurotransmitter pool are being introduced into routine clinical assessment. A reevaluation of psychogenic etiology with a consequential new concept of psy chogenic impotence is on the rise. In this book the new concepts of basic knowledge on cavernous smooth muscle function and its supraspinal, spinal, and local control; the new diagnostic approaches in psychogenic and autonomic factors; and the new developments of reconstructive therapeutic options for the patient have been tied together. Outstanding and internationally renowned experts in the field of erectile dysfunction have given detailed insight into the latest basic and clinical developments. Well-established diagnostic and thera peutic techniques are presented by experienced colleagues. We hope that this book will help the reader to get an overview of the current concepts of erection. Furthermore, we hope that international collaboration in basic and clinical research in the field of erectile dysfunction will render an update necessary in the near future.

"Endourology" provides a summary of the different endourological modalitites, especially the more advanced and controversial techniques, such as the antegrade resection of urethral valves, the transperineal I 125 seed implanations, the spoonloop resectoscope, flexible endoscopy, teflon injection to correct vesicoureteral reflux, stone manipulation in calyceal diverticula, as well as the extraperitoneal pelvioscopy. These techniques are supported by descriptions of the standard endourological procedures.

The philosophy of this NATO Advanced Research Workshop and the monograph it has yielded is that if you put a small number of very talented and creative scientists of different backgrounds and documented accomplishments together in a cloistered place for a few days to consider a very important and timely topic, many new ideas will be generated. The keynote of this conference was the Future. By this we mean the expected future developments of highly reliable sequential quantitative measurements of atherosclerotic plaque size and components in living human subjects. Some of the best minds and the most experienced and talented individuals at the leading edges of imaging of arteries were involved; some of the best scientists and students of the atherosclerotic plaque and its components participated; and some of the leading investigators of the cell biology or, as we call it in the USA, the pathobiology of atherosclerosis, contributed important new information. All of these individuals were actively involved in the conference and each obviously had carefully prepared and was able to communicate effectively.

Das Buch enth{lt eine Auswahl der Vortr{ge, die auf dem 15. Dreil{ndertreffen der deutschsprachigen Ultraschallgesellschaften gehalten wurden. Damit informiert es }ber neue technische Entwicklungen und den praktischen Einsatz in den verschiedenen medizinischen Fachgebieten.

The fetal period of human growth and development has become an area of intense study in recent years, due in large part to the development of diagnostic ultrasound. More than 2,000 articles have been published in the last five years describing anatomy and pathology in utero, as reflected in sonographic images. Yet, no stan dard reference exists to correlate these images with fetal gross anatomy and at tempts to draw parallels from adult structure have often led to false assumptions. The dictum "the newborn is not a miniature adult" is all the more valid for the fetus. This text aims to provide a comprehensive reference for normal sectional anat omy correlated with in utero ultrasound images. In addition, magnetic resonance images of therapeutically aborted or stillborn fetuses are paired with similar gross sections to serve as a foundation upon which current in vivo studies may build. Lastly, a miscellaneous section illustrates several anatomic points useful in the understanding of fetal anatomy. These points include the changing anatomy of the fetal brain during gestation and the anatomy of the meninges, the fetal heart, and ductus venosus. It is our hope that this atlas will provide a clear picture of fetal anatomy, rectify some of the confusion which exists in antenatal diagnosis, and stimulate further interest in fetal development."

The primary purpose of this book is to bridge the gap be tween the practice of clinical medicine and diagnostic radi ology. It is intended primarily for utilization by medical students in training and by nonradiologist physicians. In this world of rapidly expanding knowledge in the many specialties of medicine, it is becoming increasingly difficult for many physicians to stay abreast of the newer and constantly changing modalities of diagnosis as well as the therapeutic regimens of the common as well as the less common disease processes within their realm of practice. This book will enable the busy clinician to utilize the consultative services offered by his or her colleagues in diagnostic radiology with maximum effectiveness. The most common clinical applications of the more recent imag ing modalities (i. e. , nuclear medicine, ultrasound, comput erized tomography, and magnetic resonance imaging) have been categorized and condensed into a format that will be both comprehensible and useful on a daily basis for those physicians routinely requesting these diagnostic examina tions for their patients. For simplicity, the book is divided, whenever feasible, into organ systems and subdivided into the multiple classifications of pathologic states (i. e. , con genital, trauma or iatrogenic, inflammatory, and neo plasm). In addition, there are brief comments related to the vii specific advantages and disadvantages as well as the cost effectiveness of each modality.

Twenty years ago, the enzyme superoxide dismutase which uses the superoxide radical anion as its specific substrate was reported. With this discovery was born a new scientific field, in which oxygen, necessary for aerobi c 1 ife on thi s planet, had to be cons i dered also in terms of its toxicity and stresses. This stimulated the search for knowledge of active oxygen species in biology and medicine. Superoxide and other reactive oxygen species are now implicated in many disease processes. Major advances have been achieved during these past years with respect to free radical generation and mechanisms of free radical action in causing tissue injury. In parallel, the possibil ity of influencing free radical related disease processes by antioxidant treatment was studied in various in vitro and in vivo systems. This was the unique theme of a conference organized in Paris by the Society for Free Radical Research (December 9-10, 1988) which brought together experts from basic sciences and clinicians in order to evaluate the current status of antioxidant therapy. The conference emphasized fundamental processes in antioxidant action. Among the major topics were superoxide dismutase (SOD) and low molecular weight substances with such activity, called SOD mimics. Other antioxidant enzymes were also considered. Antioxidant vitamins, in particular vitamins E and C, other naturally occurri ng antioxidants and vari ous synthet i c antioxidants were included in the presentations as there is now a rapidly developing series of compounds with potentially interesting clinical applications.

The first edition of this definitive text ran to 24 chapters. The second edition, reflecting the explosive growth of interest in echo-enhancement, contains 44. The first section deals with some of the most important emerging issues and technologies and covers harmonic imaging, the use of echo-enhancers to provide quantitative information, and the application of enhanced power Doppler to tissue imaging. The second, on contrast echocardiography, explores the use of echo-enhancement during transesophageal imaging. One chapter describes the use of contrast-enhancement transesophageal imaging to determine coronary flow reserve and another gives a detailed account of the application of the technique to the evaluation of left ventricular function. Other authors describe the intraoperative use of contrast echocardiography and discuss the potential of myocardial contrast echocardiography to replace thallium scintigraphy. Another chapter covers the emerging technique of transient response imaging and its role in the assessment of myocardial perfusion, and two chapters are devoted to three-dimensional contrast echocardiographic assessment of myocardial perfusion. Use of echo-enhancement in the evaluation of peripheral circulation is discussed in chapters on carotid and peripheral arterial flow imaging and others that describe renal and hepatic vascular imaging. The newer applications of echo-enhancement outside the cardiovascular system are described in three chapters devoted to the visualization of tumour vasculature. The final chapters look to the future and cover the imaging of intramyocardial vasculature, the development of site-specific agents and the emergence of the new acoustically active agents.

Echo-encephalography, introduced by LEKS ELL in 1955, has gained increasing importance for the early detection of numerous intracranial lesions in the last decade. The main advantage of this diagnostic procedure lies in the fact that it permits a rapid orientation about the spatial relationships within the skull without stressing or endangering the patient. Although this method alone only rarely allows a complete diagnosis, the echo-encephalographic findings always indicate which further diagnostic measures are most suitable for establishing the diagnosis with the greatest accuracy in every case. However, the correct interpretation of an echo-encephalogram is possible only, if the findings which are assumed to be pathological are evaluated in the light of the clinical symptomatology. Since JEPPSSON'S excellent monograph on the origin of the midline echo and its importance for the diagnosis of intracranial expansivities, published in 1961, a great deal of work has gone into the development of echo-encephalography all over the world. For this reason the possibilities of this procedure today go far beyond the mere demonstration of a supratentorial shift. Now we can frequently outline the width of the ventricles exactly and localize tumors or hematomas by means of abnormal reflections. Since a detailed description of the technique, application and present-day diagnostic uses of echo-encephalography has not been available as yet, we undertook to fill this gap in the German literature in 1967 with a monograph summarizing the hitherto existing experience as well as our own extensive case mate rial.

The investigation of the brain by means of ultrasound has acquired increasing importance in the last years because it permits insight into the spatial relationships within the intact human skull in a short time without endangering the patient. The road from the first ultra sonic investigations on the exposed brain to the detection of intracranial midline shifts on the intact skull, the registration of echo pulsations and recently, to ultrasonotomography has been a long one already. However, this development is by no means at an end. Following the suggestion of numerous colleagues concerned with echo-encephalography in this country and abroad, the Neurosurgical Clinic of the University of Erlangen-Nuremberg organized an "International Symposium on Echo-Encephalography" on April 14th and 15th, 1967. Here there was an open exchange of experience on the results obtained up to the present. The limitations of the method and sources of error as well as the directions of future development of the ultrasonic echo procedure were discussed."

Marking the 200th National Meeting of the American Chemical Society, The Division of Nuclear Chemistry and Technology hosted a group of about 90 scientists from 15 different countries to discuss the new trends in radiopharmaceutical synthesis, quality assurance and regulatory control. This event took place in Washington, D.C. on August 27-30, 1990. When I first suggested the idea for this symposium, a group of scientists who pioneered the proposed topics offered their help to organize and run such a big task with me. Their names are listed here in appreciation. Thomas E. Boothe Cyclotron Facility, Mt. Sinai Medical Center, Miami Beach, Florida, USA Robert F. Dannals Division of Nuclear Medicine, The Johns Hopkins Medical Institutions, Baltimore, Maryland, USA Anthony L. Feliu Julich Nuclear Research Center, Julich, Germany Joanna S. Fowler Chemistry Department, Brookhaven National Laboratory, Upton, New York, USA George W. Kabalka Department of Chemistry, University of Tennessee, Knoxville, Tennessee, USA Hank F. Kung Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA James F. Lamb Imagents, Inc., Houston, Texas, USA Harold A. O'Brien, Jr. Los Alamos National Laboratory, Los Alamos, New Mexico, USA Joseph R. Peterson Dept. of Chemistry, University of Tennessee, Knoxville, Tennessee, USA Hernan Vera Ruiz International Atomic Energy Agency, Vienna, Austria Roy S. Tilbury University of Texas, M. D. Anderson Cancer Center, Houston, Texas, USA In addition, a number of distinguished colleagues have participated in the process of reviewing the manuscripts presented in this volume. Their effort is sincerely acknowledged.

Since the pioneering work of Donald and his first Lancet paper in 1958, the use of ultrasound in obstetrics and gynaecology has evolved rap idly. The introduction of grey scale techniques enhanced our ability to identify different tissues on the basis of their texture. However, it was the introduction of the linear array real-time scanner in the mid seven ties that changed ultrasound from being an "eccentric art form" to a readily available and usable technique. This led to the first reports of the diagnosis of neural tube defects using ultrasound by Campbell, as well as the establishment of fetal biometry. In the midst of this activity the parallel development of the transvaginal probe by Kratochwill went almost unnoticed by most gynaecologists. Yet the application of this technique has since had a major impact on many areas of gyna ecological practice, and on infertility in particular. Since the demon stration of transvaginal follicle aspiration, the vaginal route has become standard for most invasive ultrasound guided gynaecological procedures. The relatively new technical advance of transvaginal colour Doppler may potentially have just as great an impact. The introduction and use of transvaginal colour flow imaging has facili tated the study of vascular changes within the pelvis.

The second E. C. Workshop on Ultrasonic Tissue Characterization was organized for the assessment of research goals and plans as the basis to a grant proposal for a "Concerted Action" which will be forwarded to the European Commission. It should, therefore, not only be considered as a work in progress exhibition which succeeded the former activities within the E. C. (Inventory on Tissue Characterization in Europe and first Workshop). The Steering Group invited a 1 imited group of Institutes to send its group leader and a research fel low in the entitled field, who should expose the overall research program, as wei 1 as the more specific work on tissue characterization by RF signal analysis and spectroscopy. The ultimate goal of the Workshop has been the formulation of schemes of interaction among the Institutes and individuals and the definition of cooperative research programs. The remainder of the groups and some of the groups present are working in the field of analysis and processing of cl inical A- and B-mode echograms (i. e. video signals). Because this work is more closely related to the cl inical diagnostics it was decided that for that reason no preparatory workshop was needed. In the final proposal for the Concerted Action this work wi 1 1 get ample attention. Although not many clinicians were present, their positive interest in the sophisticated analysis techniques and their contribution to the dis cussions again have been a most valuable and stimulating experience."

Alfons Staudach has been a long-time member of the Anatomic Institute of Karl Franzens University in Graz, where he has devoted particular atten tion to the deeper understanding, appreciation and visualizion of gross ana tomic details. In this work the author has achieved correspondence between sonograms and anatomic sections with a consistency and persuasiveness unequaled in all the previous literature on diagnostic ultrasound. The various planes of section andtheir characteristic features, and indeed the entire format of the text, are designed to provide even the less experienced sonographer with a valuable basis for conducting his examinations. The more experienced reader will find essential information on topographic relations and organ development that is not available in any other work dealing with fetal ana to y. I am certain that my high estimation of this volume will prove justified, and that it will provice its readers with a useful and stimulating resource. Univ. -Prof. Dr. Walter Thiel (Chairman of the Anatomic Institute of the University of Graz) Foreword Anyone setting this book down after an initial perusal must wonder why such a reference was not available ten years ago. The meticulous and fas cinating juxtaposition of gross anatomic sections with sonograms, together with explanatory drawings and many practical guidelines, should enable even the novice accurately to identify details and interpret sonographic findings with precision."

Technical improvements over the past twenty years have made endos copy the procedure of choice for examination of the hollow organs of the genitourinary and gastrointestinal tracts. The development of electro surgical techniques, laser technology, injection therapy, and a wide variety of other modalities now allow the endoscopist to treat many problems that in the past required open surgery. The simultaneous development of transcutaneous abdominal sonography has had an equally dramatic impact on the practice of gastrointestinal and geni tourinary surgery. The marriage of these proven technologies, known as endoscopic sonography, provides an exciting new modality that promises to further revolutionize the diagnosis and management of many intraabdominal diseases. Endoscopic sonography opens new frontiers by overcoming the primary limitations of its parent technologies. Fiberoptic endoscopy is limited by the inability to see beyond the luminal surface, this is particularly important when considering neoplastic disease because depth of wall invasion is a key factor in determining treatment. The limiting factor in transcutaneous sonography is the distance between the transducer and the target organ. With endoscopic sonography, the transducer is placed in close proximity to the target organ. This allows the use of high frequency waves (greater than 5 MHz), which provide better tissue resolution and eliminates the image distortion caused by overlying structures.

Since the beginnings of diagnostic ultrasound in the 1950s, each decade has seen significant advances in this technology. Commer cialization of ultrasound occurred during the 1960s with the introduction of many of the clinical uses that are in existence today. The 1970s showed the most dramatic changes with the commercial introduction of gray-scale and real-time ultrasound. In the 1980s many new advances were introduced, including color Doppler, as well as a wide variety of endoluminal approaches, including endorectal, endovaginal and transesophageal. The decade of the 1990s promises even more significant advances with further transducer miniaturization, three-dimensional ultra sound, and the introduction of a variety of ultrasound contrast agents. With such rapid changes occurring, it becomes important to disseminate knowledge in as rapid a fashion as possible, thus it was quite appropriate that a meeting such as this be held to provide an in-depth review of the many new areas of ultrasound imaging that show promise for the future. Emphasis was on the new uses of ultrasound in gastrointestinal diseases. Many of these advances will, of course, also have applications in many other areas of the body. It is hoped that those in attendance will acquire a much broader understanding of where ultrasound is now and where it is headed in the not too distant future.

Only a few years ago, most treatises on sonography covered all the diagnostic applications of ultrasound, de scribing organs from the brain down to the placenta. Dr. Bruneton and his associates must be thanked for pre senting this book devoted to the spleen. It probably offers the most complete presentation of details and the richest images available in its field. This book will thus become the ultimate reference in most libraries of books on son ography. March 1988 F. Weill The authors wish to thank Christine Rostagni, Fran ise Fein, and Bernard Fontaine for their assistance in the preparation of this book. Contents 1 Sonographic Anatomy of the Normal Spleen, Normal Anatomic Variants, and Pitfalls B. Senecail . . . . . . . . . . . . . . . . . . . . . . 1 1. 1 Anatomy of the Spleen. . . . . . . . . . . . . . . . 1 1. 1. 1 Morphology and Structure . . . . . . . . . . . . . 1 1. 1. 2 Location and Relations of the Spleen. . . . . . . . 3 1. 1. 3 Average Dimensions of the Cadaver Spleen . . . . 5 1. 1. 4 Congenital Anomalies and Normal Variants. . . . 5 1. 1. 4. 1 Fissured Spleen. . . . . . . . . . . . . . . . . . . . 5 1. 1. 4. 2 Lobulated Spleen. . . . . . . . . . . . . . . . . . . 5 1. 1. 4. 3 Spleen with Two Hili. . . . . . . . . . . . . . . . . 5 1. 1. 4. 4 Wandering or Ectopic Spleen . . . . . . . . . . . . 6 1. 1. 4. 5 Numeric Anomalies . . . . . . . . . . . . . . . . . 6 Ultrasonography of the Spleen . . . . . . . . . . . 1. 2 6 1. 2. 1 Equipment . . . . . . . . . . . . . . . . . . . . . . 6 1. 2. 2 Patient Examination . . . . . . . . . . . . . . . . . 7 1. 2. 3 Scanning Technique . . . . . . . . . . . . . . . . . 7 1. 3 Sonographic Features of the Normal Spleen. . . . 7 1. 3. 1 Splenic Contour . . . . . . . . . . . . . . . . . . . 7 1. 3. 2 Echo Pattern of the Splenic Parenchyma. . . . . ."

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.

Congenital hip dysplasia and dislocation are common diseases of newborns and small infants, with frequently severe consequences if orthopaedic therapy is not initiated at an early stage. Therefore many clinicians have been looking for a simple method for the investigation of the hip joint in the early neonatal period. Up to 1980 the diagnosis of hip dysplasia could usually not be made before the 3rd month of life, by means of pelvic roentgenography. Only incomplete or complete unilateral dislocations were diagnosed in the neonatal age group. In 1980, however, Graf, an Austrian orthopaedic surgeon, began using ultrasound investigation ofthe hip joint in newborns and small infants in order to make an early diagnosis and to avoid radiation exposure. The intention of the present study was to compare ultrasound of the hip joint with other established diagnostic procedures and to establish whether it is suitable as a screening procedure in newborns. 2 Incidence of Congenital Hip Dysplasia and Dislocation In 1972 Barlow reported that 90 % of hips which are unstable at birth develop to normal joints spontaneously without any therapy. Visser (1984) thus suggested determining the percentage of hip dislocations after the 2nd - 3rd month of life so that children with spontaneous stabilisation would be excluded.