Cardiovascular fluid mechanics is now used as a tool in determining diagnosis, treatment, and prognosis by physicians and surgeons working in the fields of cardiology and angiology. The text is based on a considerable amount of clinical and experimental data on blood flow in the heart and large vessels obtained using various methods such as ultrasound pulsed Doppler velocimetry (including Doppler color flow imaging), catheter-tip electromagnetic velocimetry, hot-film anemometry, and laser Doppler velocimetry. The book will introduce medical researchers and clinicians to this rapidly developing field and allow them to apply the knowledge and the methods of fluid mechanics to practical medicine.

Echocardiography has now reached its maturity and plays a key role in the clinical assessment of cardiac function. However, its ability to assess myocardial perfusion remains a clinical challenge.

Myocardial contrast echocardiography is a technique that uses microbubbles. These microbubbles remain entirely within the intravascular space and their presence in any myocardial region denotes the status of microvascular perfusion within that region. During the last few years, a large number of research studies have been dedicated to this topic. The latest developments in echocardiographic techniques and second-generation contrast agents allow for the potential assessment of myocardial perfusion and provide an accurate endocardial border delineation.

In the present book, these new echocardiographic techniques dedicated to the assessment of myocardial perfusion are described in detail by experts from both sides of the Atlantic. Tips and tricks are included, explaining the basic concepts that are needed to understand and perform contrast echocardiography.

The opacification of the left ventricle by echo cardiographic contrast agents (echoventriculography) represents an alternative to cineventriculography, as determinations of left ventricular volume and ejection fraction are accurate and highly reproducible, when methods like color superposition and statist- ical imaging techniques are used in order to improve the outlining of the cavity and endocardial border. Detection of perfusion defects is possible [40]. The enhancement of myocardial contrast during the perfusion phase after injection into the left ventricle or the aorta further improves the endo- cardial border delineation. For practical purposes, the direct injection of echocardiographic contrast is inferior to the indirect opacification after per- ipheral venous injection which can be achieved with sonicated albumin, Albunex(R), SH U 508 A, HOE 155. These drugs are presently under clinical investigation. In up to 90% of the patients, left heart opacification is possible, yielding 30% intensity of the right ventricle. When these drugs are available, sophisticated computed methodologies have to be included in the echocardio- graphic machines in order to improve the determination of the left ventricular volume and ejection fraction [44]. In the future, cineventriculography will be rarely performed as echoventriculograms already show left ventricular contraction. This will possibly result in reduced side effects and costs. REFERENCES 1. Gramiak R, Shah PM, Kramer DH. Ultrasound cardiography: Contrast studies in anatomy and function. Radiology 1969; 939. 2. Kronik G, Hutterer B, Mosslacher H. Diagnose atrialer Links-rechts-Shunts mit Hilfe der zweidimensionalen Kontrastechokardiographie. Z Kardiol 1981;70:138-45.

The disorders induced by iodine deficiency affect at least one billion people. Because ofits effects on brain development, iodinedeficiency is the single most preventable cause of mental retardation in the world. Therefore, the United Nations and the Heads of State of almost all the world's countries represented at the Summit for Children in 1990 adopted resolutions to eradicate the disorders induced by iodine deficiency (IDD) by the year 2000. For geological and socio-economic reasons, most of the populations affected by iodine deficiency disorders live in isolated and usually mountainous areas, in pre industrialized parts ofthe world. The problem of iodine deficiency in Europe has been greatly underestimated in the last decades. After the remarkable studies on the effects of iodine deficiency and their prevention and correction in Switzerland, IDD was generally considered no longer a significant public health problem in Europe. However, surveys carried out in the early 1980's under the auspices of the European Thyroid Association, clearly demonstrated the persistence of moderately or even severely affected areas. These surveys also highlighted the lack ofinformation about large parts ofEurope, especially its eastern part. It is only quite recently, following major changes in international relations and thanks to the support of UNICEF, WHO, the International Council for the Control of Iodine Deficiency Disorders and the European Thyroid Association, that more extensive surveys have been conducted in several parts of Europe hitherto almost unexplored. These surveys showed that most European countries were iodine deficient."

The origin ofthe International Acoustical Imaging Symposium series can be traced to 1967, when a meeting on acoustical holography was held in C alifornia. In those days, acoustical holography was at the leading edge of research but, as the importance of this subject waned, so the title of the series was changed from Acoustical Holography to Acoustical Imaging in 1978. The early Symposia were held at various venues in the United States. In 1980. the series became international, with the Symposium that year taking place in Cannes in France. The pattern now is to try to met alternately in the USA and in another part of the world so that active researchers everywhere can conveniently attend at a reasonably high frequency. It was a great privilege for us in Bristol in the United Kingdom to be chosen to host the 25th Symposium, which convened on 19 March 2000 and spread over four days. We were blessed not only by good weather, but also by the attendance ofnearly 100 pa rticipants who came from 17 c ountries. A large number of papers were accepted for presentation, either orally or as posters. Whether an oral presentation or a poster, all were considered to have equal merit, and no distinction is made between them in the published proceedings. There were no parallel sessions, so every participant could attend every presentation. The re sultant disciplinary cross fertilisation maintained the t radition of past Symposia.

There are many human cancers which actively synthesize specific characteristic proteins such as melanomas, thyroid cancer and squamous cell carcinoma. Many cancer researchers have of course tried to utilize this specific activity as a key for the selective treatment of cancers. In the past for example, the molecular hybrid compound of DOPA, a substrate of melanin, and nitrogen mustard N-oxide hydrochloride, a ctyotoxic anti-tumor drug, was synthesized as Melphalan and used to treat malignant melanoma. A major problem arose though in that it was soon found to be highly suppressive toward bone marrow and quite toxic while not being remarkably effective. Thus, malignant melanoma could not be cured by it. Such failure led us to develop a novel bimodal therapeutic system which includes the use of non-toxic potentially cytocidal chemicals which selectively accumulate within the cancer cells and which are converted by a controllable modality into an actively cytocidal element in situ. We can now non-surgically cure malignant melanoma and glioblastoma with our selective cancer treatment, neutron capture therapy (NCT); as can be found in this volume. Included are 124 papers on the latest breaking developments discussed at the Sixth International Symposium on NCT for Cancer held in Kobe during the late autumn of 1994.

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.

Diagnostic and Therapeutic Ultrasound has recently taken an explosive growth for better safer, economic, mobile and high quality healthcare. This technology is very appealing for medical applications because it is non-ionizing, non-invasive and it is available in most of the medical and clinical facilities. Its low cost, when compared with other medical image modalities, makes it one of the preferred tools for medical monitoring, follow-up and diagnosis. Besides the traditional fields of Cardiology and Obstetrics, where it is extensively used for long time, it has became also very useful in the diagnosis of diseases of the prostate, liver and coronaries and carotids atherosclerosis. However, Ultrasound images present poor quality, very low signal to noise ratio and a lot of artifacts. The extraction of useful information from Ultrasound data for diagnosis is a challenge task that makes this medical image modality a very active field of research. The difficulties are being overcome and novel and advanced methods are being proposed for detection, characterization and segmentation of abnormalities in several organs. In fact, Ultrasound application range is vast, covering almost all organs of the human body, including the brain where Tran-cranial Doppler Ultrasound is very important to assess the brain vasculature. This book presents some of the recent advances in Ultrasound imaging technology covering several organs and techniques in a Biomedical Engineering (BME) perspective. The focus of the book is in the algorithms, methodologies and systems developed by multidisciplinary research teams of engineers and physicians for Computer-Aided Diagnosis (CAD) purposes. Cardiovascular and Cancer, the most common life-threatening diseases in western countries, are two of the most important topics focused in the book. However, other advanced issues are also presented such as Intravascular Ultrasound, 3D US and Ultrasound in Computer-Aided Surgery (CAS). Some chapters are direct contributions from medical research groups where Ultrasound has also received great attention in the last decade. By this, new techniques based on Ultrasound were introduced in the clinical practice for diagnosis and therapeutics, mainly in hospital facilities.

General Section. Progress in laparoscopy (new instruments, technical innovations, integration between laparoscopy and sonography). Special Section. Traditional and present indications for laparoscopy. Laparoscopy inliver diseases. Oncological lapaoscopy (diagnosis, staging and follow-up for malignant tumors). Emergency laparoscopy.

Regional anaesthesia is used across specialties within anaesthesia, and is a rapidly growing sub-specialty. This new handbook covers both traditional and ultrasound guided techniques, concentrating on the differences between them. Offering readers a comprehensive overview for clinical practice, it includes paediatric and acute pain applications. Each topic covers anatomy, contraindications, landmark/US settings, technique, complications, and clinical notes. Discrete sections on pharmacology, principles, and training further the book's use for teaching purposes. It will appeal to both trainees and consultants in regional anaesthesia, as well as anaesthetic nurses and anaesthetic practitioners. Presented in the Oxford Specialist Handbook series, it offers practical advice as well as background information in a convenient pocket-sized title.

Renal sonography forms a basic part of routine diagnostic strategy. This textbook summarizes eighteen years of experience in diagnostic ultrasound. We want it to serve as a guide to both imagers and mere consumers of information. That is why we shall emphasize practical advice and diagnostic pitfalls; it is also why we shall often deal with the relations of sonography with other diagnostic procedures, which it may complement or replace, precede or follow, the purpose being to achieve efficiency at low cost. We shall limit our subject matter to the kidney itself and the neighboring retroperitoneal compartments, dealing only briefly with the lower urinary tract, which requires specialized procedures. We devoted considerable space to renal sonography in our book Clinical Atlas of Ultrasonic Radiography, published in 1973. Since then, nothing has changed and everything has changed. Nothing, because even then the differential diagnosis between a solid and a cystic mass, the etiologic diagnosis of a nonsecreting kidney, and the positive diagnosis of a traumatic juxtarenal hematoma were quite reliable, making possible drastic reductions in the indications for instrumental roentgenologic examinations. Everything, be cause improved resolution and grey scale imaging (already partially achieved in 1973, thanks to real time) have profoundly refined both anatomic and pathologic ultrasonic studies. And now high resolution real time imaging has revolutionized renal examination techniques, whereas Doppler is entering routine ultrasonic diagnosis."

There are two major reasons for having this symposium. First, Tohoku Univer sity is the place where ultrasound investigations in Japan originated. Starting from the research studies of Professors H. Nukiyama and Y. Kikuchi of To hoku University, Professor J. Saneyoshi of Tokyo Institute of Technology, and Dr. K. Kato of Osaka University - all graduates of Tohoku University - the results spread to all parts of Japan. More recently we have had acoustic macro scopic studies by researchers like Professor N. Chubachi. As regards tissue char acterization, which was the main theme of the symposium, the collaboration among research workers in Japan and the United States started 10 years ago between Professor F. Dunn of the University of Illinois and staff members of Tohoku University and the Tokyo Institute of Technology. So this conference commemorates the lOth anniversary of that joint research effort. The second reason for this conference is that the application of ultrasound has become wide spread and indispensable in the routine clinical activities of medicine. But there have not been many breakthroughs in terms of quantitative and qualitative measurement of the living body tissues. Also, there are many problems with regard to practical application. There are various points that have not been elucidated yet as to the physical and acoustical characteristics of ultrasound itself. The methodology has not in all cases been well established. Therefore, the scientific elucidation of these areas is essential.

Digital radiography is a general term describing any projection radiological system in which the image exists in digital form at some stage between acquisition and viewing. In an earlier form, radiographic films were dig itized in an attempt to enhance and redisplay information of interest. The field has evolved to its current state, in which X-ray signals are detected electronically, converted to digital form, and processed prior to being recorded and displayed. A primary goal of digital radiography is the re moval of interfering effects from secondary structures in an image, so that clinically significant details can be displayed with enhanced visibility. The achievement of this goal involves many parameters, including con trast agents, subtraction techniques, processing techniques, filtering tech niques, system noise, and quantitative aspects. It is the purpose of this book to present material by noted individuals in the field covering several of the above topics. The authors acknowledge the secretarial and editorial assistance of Mrs. Helen Taylor and the editorial assistance of Mrs. Ruth McDevitt. James G. Kereiakes Stephen R. Thomas Cincinnati, Ohio Colin G. Orton Detroit, Michigan ix Contents 1. DIGITAL RADIOGRAPHY: OVERVIEW B. A. Arnold, 1. G. Kereiakes, and S. R. Thomas 1. Introduction . . . . . . . . . 1 2. Point-Scanned Detector Systems 3 3. Line-Scanned Detector Systems 4 4. Area Detector Systems 5 4.1. Stimulable Phosphors 5 4.2. Selenium Detectors ."

Despite the many advances made in the diagnosis and therapy of cancer, the mortality rate is still about half that of the incidence rate. However, the odds are not evenly distributed. Prognosis for some cancers is good, but for others, few patients will survive 12 months. This latter group of cancers is characterised by a proclivity to disseminate malignant cells in the host organ. The degree of surgery possible may be limited by the critical nature of the organ, and chemotherapy and radiotherapy are of palliative value only. In some cases systemic metastases occur, but in other cases, failure to achieve local control results in death. First among these cancers are the high grade brain tumours, astrocytoma 3,4 and glioblastoma multiforme. Local control of these tumours should lead to cure. Other cancers melanoma metastatic to the brain, for which a useful palliative therapy is not yet available, and pancreatic cancer for which localised control at an early stage could bring about improved prognosis. Patients with these cancers have little grounds for hope. Our primary objective is to reverse this situation with Neutron Capture Therapy (NCT). The purpose of this fourth symposium is to hasten the day whereby patients with these cancers can reasonably hope for substantial remissions. The first symposium on NCT was held in Boston in 1983, followed by Tokyo in 1985 and Bremen, Germany in 1988.

An international meeting of experts on Cardiovascular Imaging by Ultrasound was held in Aachen from 26-27 April, 1991. It provided new and interesting insights into what has already been achieved in ultrasound-based cardiovascular diagnosis and therapy and what will be introduced in clinical practice in the near future. Since the introduction of ultrasound in clinical practice in 1984 there has been no other physical principle that has added and will continue to add so much to clinical diagnosis and therapy. Echocardiography, once established as a non-invasive diagnostic tool, is increasingly becoming an invasive technique for cardiovascular imaging. This book contains the edited contributions from 38 scientists and engineers from all over the world who presented the most up-to-date findings on 2-dimensional echocardiography, different Doppler modalities, contrast and stress echocardiography and the different modalities of transesophageal echocardiography, including mono-, bi- and multiplane TEE, as well as pulsed and CW-Doppler application via TEE. Exciting and promising developments are discussed in the field of intravascular ultrasound, tissue characterization, ultrasound ablation, ultrasound-based 3-dimensional reconstruction of the heart, and high frequency Doppler analysis.

It is now 150 years ago, on 25th May 1842, that the son of a Salzburg ston emason presented a scientific work "On the coloured light of the double stars and certain other heavenly bodies" at a meeting of the Royal Bo hemian Society of Sciences held in Prague. Christian Andreas Doppler, then professor at the Prague Technical Institute, set a milestone in scien tific history in the meeting room of the Royal Society in the Charles Uni versity, just a few meters from the National Theatre where another genius from Salzburg, Wolfgang Amadeus Mozart, had celebrated his musical triumph with the premiere of his opera Don Giovanni fifty-five years earlier. Doppler's lecture set out in brilliant simplicity what we now call the Doppler principle, which since has found numerous uses in astronomy, which was of primary interest to Christian Doppler. In addition, it has found countless practical applications in physics, navigation, aeronautics, geodesy, medicine, science and technology. In medicine alone, Doppler sonography is now an established diagnostic procedure in the fields of childbirth, cardiology and diseases of the blood vessels, neurology, neuro surgery and vascular surgery, and is continually finding new medical appli cations in today's world of high technology."

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.

Ultrasound (US) prenatal screening has been proposed as the most effective technique for Trisomy 21 early assessment. Assessment of Nuchal Translucency (NT) offers promising non-invasive method for fetal abnormalities detection up to 75%. Nevertheless, current clinician practice of NT examination by locating the sonogram calipers on 2D US image requires highly trained and competent operators by adhering to a standard tedious protocol; therefore it is prone to errors and hence it decreases the reliability in intra- and inter-observer repeatability. This Brief provides the basic knowledge regarding Trisomy 21 diseases and its existing detection methods. The restrictions and disadvantages of each method are discussed accordingly. Therefore, a non-invasive early detection method using 3D ultrasound reconstruction of Nuchal Translucency is introduced. This new method for 3D NT assessments has an edge over the previous 2D methods, and entails the composite function in visualizing the explicit internal marker structure. Further, image processing techniques covered from data acquisition, pre-processing, speckle noise reduction and 3D segmentation are also discussed. This should be especially useful for students and professional researchers in the Biomedical and image processing fields.

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.

Endoanal and endorectal ultrasound represents considerable progress in the field of anorectal imaging. Its importance in the staging of rectal and anal cancer, in identifying perianasto- motic neoplastic recurrences, in defining acute and chronic suppurative disease and in assessing sphincteral anatomical integrity, is now a confirmed reality. The evidence provided by endoanal and endorectal ultrasonography guides the colorectal surgeon in his choice among the various therapeutic approaches and helps in assessing the effects of the treatments applied. The great flexibility and high degree of reliability make this exploratory method an indispensable tool at all stages of the clinical course in the majority of patients with anorectal problems, including the fundamental follow-up stage. The publication of this excellent volume on intraanal and intrarectal ultrasonog- raphy is therefore to be appreciated, especially since it is in the form of an atlas. As we are dealing with imaging, it is particularly appropriate that it is the images that tell the story. Like all important things, this volume does not come out of nothing. It is the result of many years of skilled work by Drs. G.A. Santoro and G. Di Falco and is based on the experience of internationally renowned professional experts. The ten sections of the atlas begin with general information on ultrasonography, gradually progressing to the technical problems of the method and the aspects rela- tive to anorectal tumors.This last section leads to a review of traditional and mod- ern therapeutic possibilities.

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.

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.