Very thorough knowledge of breast pathology is a sine qua non for interpretation of breast films ... progress in X-ray diagnosis could only be made by careful comparison of the film with the actual specimen. H.INGLEBY Multiplication of the same e"oneous diagnosis does not make that diagnosis co"ect. J.G.AzZOPARDI Paradoxically enough, our specialty considers the radiologist who mis takes a skin fibroma or the calcifications in a sponge kidney for a kid ney stone to lack basic knowledge, while the radiologist who imme diately calls for the surgeon because of a few white spots on a mammogram is thought to be acting according to the rules of medical practice. Misunderstandings and confusion with regard to breast pathology as well as the comfortable philosophy that superfluous biopsies are the price we have to pay for the early detection of carcinomas have in many places led to a loss of confidence in mammography. Yet this is a meth od with which carcinomas can be detected earlier than with any other imaging technique.

The clinical acceptance of computed anatomic cross-sections. Schematic line tomography (CT) as an integral part of our drawings are also generously used to il diagnostic armamentarium was based on its lustrate particularly complex anatomic re ability to display cross-sectional anatomy gions and help the reader obtain a correct with near anatomic precision. However, perspective on these more difficult regions. the radiologist must first be knowledgeable The book successfully presents a clear per of the complexities of normal anatomy be spective on the anatomy we see daily in fore he can truly make full use of this tech using cross-sectional imaging techniques. nology. This book will prove useful as a learning Michael Farkas has truly made our task guide for the uninitiated, and as a refer as radiologists easier. As noted in the ence for the more experienced. Either preface, the book carefully correlates rep way, it is an important contribution to our resentative CT slices with corresponding literature. Elliot K. Fishman, M.D."

When I planned this book seven years ago I had my graduate students at the University of Ulm in mind, diploma as well as doctoral students, who often asked me what literature they should work with. I used to suggest a list of ten to twenty (for my taste: excellent) treatises on NMR. Apparently this did not make them entirely happy. The difficulty which newcomers to the field face is to practise and to apply theoretical formalisms from different sources while still learning the principles of NMR and being actively engaged in NMR research. Although the text presented here is largely based on my lecture notes, the result is a "working book" rather than an introduction. It is intended to provide direct access to the basic information one needs for NMR diffusometry, relaxometry, and tomography applications. A "working book" is certainly not suitable to be read starting on page one and then carrying on until the last page. Boldly extrapolating my own reading habits to those of the typical scientist I am sure that this is not the way in which monographs of this kind are read nowadays. So my aim was to produce a treatise that offers easy and quick access for the reader to relevant matters of interest. I tried hard to ease the comprehension of NMR principles by extensive cross-referencing among the sections and chapters. Tomography, diffusometry and relaxometry are fields based on common phys ical principles."

The esophagus, ostensibly a simple tubular structure whose functional role often is minimized and even ignored, is, in re- ality, a highly complex viscus. The problems associated with disorders of the esophagus are not only related to the usual en- tities which may be anticipated in any portion of the gastroin- testinal tract, but include in a major fashion the functional mechanisms indigenous to the pharyngoesophageal and eso- phagogastric junctions. A number of disorders, representative of the classical cate- gories of disease, affect the esophagus. These include the various congenital and developmental abnormalities, of which some are complex. Trauma to the esophagus is not un- common, and infective and inflammatory lesions of this struc- ture are encountered relatively frequently. The different types of neoplasms of the esophagus are relatively few in number, but are commonly observed-the most serious, from the point of view of survival, being carcinoma. The collagen disorders, particularly scleroderma and dermatomyositis, affect the eso- phagus all too often. A miscellaneous group includes such en- tities as achalasia and varices, occurring in varying degrees of frequency. Functional abnormalities of the oropharynx, hypo- pharynx and esophagus, particularly relating to swallowing and the frequently encountered instances of spasm of the pharyngoesophageal and the esophagogastric junctions, consti- tute an important and common source of difficulty in the pa- tient population at large. In this regard, anatomic, radiologic, and physiologic studies of these structures have provided through the years vital data which has proved of considerable VII ...

La radiologie digestive a ete pendant de nombreuses decennies Ie fleuron de la radiologie fran

The purpose of this series of volumes is to present a comprehensive view of the complications that result from the use of acceptable diagnostic and thera peutic procedures. Individual volumes will deal with iatrogenic complications involving (1) the alimentary system, (2) the urinary system, (3) the respiratory and cardiac systems, (4) the skeletal system and (5) the pediatric patient. The term iatrogenic, derived from two Greek words, means physician-in duced. Originally, it applied only to psychiatric disorders generated in the patient by autosuggestion, based on misinterpretation of the doctor's attitude and comments. As clinically used, it now pertains to the inadvertent side effects and complications created in the course of diagnosis and treatment. The classic categories of disease have included: (1) congenital and developmen tal, (2) traumatic, (3) infectious and inflammatory, (4) metabolic, (5) neoplastic, and (6) degenerative. To these must be added, however, iatrogenic disorders a major, although generally unacknowledged, source of illness. While great advances in medical care in both diagnosis and therapy have been accomplished in the past few decades, many are at times associated with certain side-effects and risks which may result in distress equal to or greater than the basic condi tion. Iatrogenic complications, which may be referred to as "diseases of medical progress," have become a new dimension in the causation of human disease."

As an addition to the European postgraduate training system for young neurosurgeons we began to publish in 1974 this series devoted to Advances and Technical Standards in Neurosurgery which was later sponsored by the European Association of Neurosurgical Societies. The fact that the English language is well on the way to becoming the international medium at European scientific conferences is a great asset in terms of mutual understanding. Therefore we have decided to publish all contributions in English, regardless of the native language of the authors. All contributions are submitted to the entire editorial board before publication of any volume. Our series is not intended to compete with the publications of original scientific papers in other neurosurgical journals. Our intention is, rather, to present fields of neurosurgery and related areas in which important recent advances have been made. The contributions are written by specialists in the given fields and constitute the first part of each volume. In the second part of each volume, we publish detailed descriptions of standard operative procedures, furnished by experienced clinicians; in these articles the authors describe the techniques they employ and explain the advantages, difficulties and risks involved in the various procedures. This part is intended primarily to assist young neurosurgeons in their post graduate training. However, we are convinced that it will also be useful to experienced, fully trained neurosurgeons."

The NATO Advanced Study Institute (ASI) on Physics and Engineering of Medical Imaging has addressed a subject which in the wide area of biomedical technology is one of those which are showing greater impact in the practice of medicine for the ability to picture both Anatomy and Physiology. The information and accuracy obtained by whatever imaging methodology is a complex result of a multidisciplinary effort of several sciences such as Physics, Engineering, Electronics, Chemistry, Medicine, etc ... Development has occurred through work performed in different environments such as basic and applied research laboratories, industries and clinical centers, with the aim of achieving an efficient transfer of know-how and technology for the improvement of both investigation possibilities and health care. On one hand, such an effort requires an ever-increasing committment of human and financial resources at research and industrial level, and, on the other, it meets serious difficulties in recruiting the necessary human expertise oriented to this technology which breaks with the tradi tiona I academic borders of the single disciplines. Furthermore, the scientific community is continually dealing with the problem of increasing the performance and, at the same time, complexity and costs of instruments, applying more and more sophisticated technology in an effort to meet the demand for more complete and accurate clinical information. The scientific program of this ASI and the qualification of the authors reveals the intrinsic complexity of the development process of the Imaging methodologies.

There are two important reasons for publishing this new series entitled "Advances and Technical Standards in Neurosurgery": 1. the lack of any organized common European postgraduate training system for young neurosurgeons and 2. the language barriers, which impede the exchange of neurosurgical findings in Europe more than in other parts of the world. The fact that the English language is well on the way to becoming the international medium at European scientific conferences is a great asset in terms of mutual understanding. Therefore the Editors have decided to publish all contributions III English, regardless of the native language of the authors. All contributions are submitted to the entire editorial board before publication of any volume. Our series is not intended to compete with the publications of original scientific papers in other neurosurgical journals. Our intention is, rather, to present fields of neurosurgery and related areas in which important recent advances have been made. The contributions are written by specialists in the given fields and constitute the first part of each volume. In the second part of each volume, we publish detailed descriptions of standard operative procedures, furnished by experienced clinicians; in these articles the authors describe the techniques they employ and explain the advantages, difficulties and risks involved in the various procedures. This part is intended primarily to assist young neurosurgeons in their postgraduate training. However, we are convinced that it will also be useful to experienced, fully trained neurosurgeons.

Cardiac ultrasound has rapidly developed into one of the most important clinical methods for diagnosis and follow-up of patients with heart disease and has changed the practice of cardiology permanently. In addition to improving image quality, most of the progress relies on digital image acquisition, storage, and quantitative analysis equipment. Automatic endocardial detection and three- dimensional reconstruction are now being developed. The progress with contrast echocardiography for myocardial perfusion imaging and results with tissue characterization is slow, but ever increasing, illustrating that the full potential of the method has not yet been explored. All of these digital techniques are extensively dealt with in this volume. Computerized tools will help the clinical cardiologists in their daily practice and stimulate further development to gen- uinely improve patient care in the coming years. We wish to thank the authors to this volume for their excellent contribution and Mrs. T. van der Kolk for secretarial assistance. IX Contributors F. J. ten Cate Thorax Center, Erasmus University, P. O. Box 1738, 3000 DR Rotterdam, The Netherlands R. Erbel II Medical Clinic, Johannes Gutenberg University, Langenbeckstr. 1, P. O. Box 3960, D-6500 Mainz, FRG Co-authors: R. Zotz, B. Henkel, G. Schreiner, C. Steuernagel, R. Zahn, H. Kopp, W. Clas, R. Brennecke, P. Schweizer, J. Meyer S. B. Feinstein Division of Cardiology, Box 44, University of Chicago, 950 East 59th Street, Chicago, IL 60637, USA D. G. Gibson Department of Cardiology, Brompton Hospital, Fulham Road, London SW3 6HP, UK Co-author: R. B. Logan Sinclair E.

Proceedings of the 9th Conference, Washington D.C., 10-14 June 1985 Sponsored by the Clinical Center and the Fogarty International Center of the National Institutes of Health, Bethesda, Maryland, USA

The decision of Harvey Cushing to leave general surgery and concentrate on the infant field of central nervous system surgery was in retrospect a landmark in the history of neurosurgery. His concentrated work, and also that of his colleague Walter Dandy, originated with the desires of both pioneers to understand surgical anatomy and neurophysiology. The fundamental knowledge and surgical techni ques that they provided became the standard of excellence for several generations of neurosurgeons; so much so that the general belief was that the surgical techniques could not be improved upon. Twenty-five to thirty years ago microtechniques began to appear in a few surgical research centers, they were then gradually applied to clinical neurosurgery and have contributed to a new level of understanding in surgical anatomy and neurophysiology. We are now fortunate to have a new standard of morbidity and mortality in the surgical treatment of intrathecal aneurysms, angiomas, and tumors. It has been said that microneurosurgery was reaching its limits, especially when treating lesions in and around the cavernous sinus and skull base; those lesions notorious for involvement of the dural and extradural compartments, with a tendency to infiltrate adjacent nerves and blood vessels. The dangers of uncontrollable hemorrhage from the basal sinuses and post-operative CSF rhinorrhea appeared unsurmountable. The lateral aspects of the petro-clival region have been of interest to a few pioneering ENT surgeons and neurosurgeons but the cavernous sinus in most respects has remained the final unconquered summit."

Echocardiography has recently become one of' the most important techniques in clinical cardiology. The major advantage of this method is its noninvasive nature enabling us to apply it under a widespread variety of clinical conditions. In the late 1960s, when research and clinical application of echo cardiography were started, and during the first decade investigations were mainly focused on the morphology of the valves and the chambers of the heart. The introduction of two-dimensional echocardiography was a major breakthrough in visualizing different portions of the heart. How ever, the poor resolution of the first devices provided only little qualitative information. With the introduction of phased array 2-D-echo-devices yielding better results and the application of computer techniques for the processing of M-mode and two-dimensional echo cardiograms, a great amount of qualitative information has become available to describe not only the morphology, but also the dynamic function of the heart in a noninvasive manner. This volume summarizes the lectures held at the International Symposium on Echocardiography, Hamburg, September 1978, endeavoring to review the current state of knowledge with regard to echo cardiography in the experimental and clinical setting. We herewith thank all lecturers, who have contributed to the publication and the Pharma-Schwarz Company which enabled us to organize this meeting by a generous subsidy."

This is a unique book in that it brings together the two key investigative techniques in Gynaecology and Obstetrics, namely ultrasound and endoscopy. So often in the past they were regarded by their exponents as rival techniques but it is now recognised that they are complementary to each other. Consequently future trainees in endoscopy should become efficient in transvaginal sonography and vice versa. Ultrasound can be used to study the morphology of the pelvic organs such as the endometrium, myometrium and ovaries, and being non-invasive, safe and convenient can be repeated as often as is deemed necessary to monitor changes over time; for example in the investigation of the infertile woman the development of the dominant follicle, the maturation of the endometrium and the formation of the corpus luteum can be documented throughout the menstrual cycle while growth of ovarian cysts can be precisely measured to determine the need for surgery. A seldom-mentioned strength of the ultrasound examination is its interactive quality, for example by performing abdominal palpation during the scan, the mobility of the uterus and ovaries can be assessed. Also the images as they appear can be shown to the patient to aid understanding. Ultrasound can also determine function and the use of Doppler has been used for example to access endometrial receptivity, follicular maturity and the likelihood of malignancy in the endometrium or ovary.

This book is not intended as a general text on MRI. It is written as an intro duction to the field, for nonexperts. We present here a simple exposition of certain aspects of MRI that are important to understand to use this valuable diagnostic tool intelligently in a clinical setting. The basic principles are presented nonmathematically, using no equations and a minimum of symbols and abbreviations. For those requiring a deeper understanding of MRI, this book will help facilitate the transition to standard texts. Chapters 1 through 4 provide a general introduction to the phenomenon of nuclear magnetic resonance and how it is used in imaging. Chapter 1 discus ses magnetic resonance, using a compass needle as an example. In Chapter 2, the transition to the magnetic resonance of the atomic nucleus is made. Chapter 3 describes the principles of imaging. In Chapter 4, the terms T 1 and T 2 are described and their relationship to tissue characterization; the fun damental role of thermal magnetic noise in T 1 and T 2 is discussed.

An Advanced Study Institute on Ultrasonics in Medical Diagnosis was held in Milan, Italy, from 10 to 15 June 1974. This ASI was of a short five-day duration and limited to cardiac diagnosis by ultra sound only. Since that time, the field of diagnostic imaging in medicine has literally exploded with new and improved means of medical diagnosis such as computed tomography, microwaves, nuclear magnetic resonance and other sophisticated techniques. These developments have enabled medical practitioners to make diagnoses with a minimum of danger to the patient, and a maximum of accuracy never before possible, and represent a multi-quantum advance over the early state-of-the-art presented at the 1974 ASI. Since then, several meetings have taken place on these individual topics to bring together experts who presented their latest research results, but none have discussed the entire field of diagnostic imaging in medicine in one meeting nor have they had the teaching character of an Advanced Study Institute. The art and science of medicine have been altered repeatedly during the eight year interval since the last ASI. Today's clinician must be part technologist and must be enough of an investigator to understand and appreciate the scientific method. The current complex advances in instrumentation and pharmacology have had a marked effect on how medicine is practiced. There was, therefore, an urgent need to bring the entire field of imaging in medicine to one teaching podium where the many advances of the last six or seven years could be reviewed.

J.J. Broerse, Radiobiological Institute TNO, Rijswijk, The Netherlands, and T .J. MacVittie, Armed Forces Radiobiology Research Institute, Bethesda, MD, USA. During the past decade, relatively few new studies have been initiated on the response of different species to high-dose, total-body irradia- tion. For information on the LDSO/30d (the dose which produces 50 percent lethality within 30 days), one is generally referred to the older literature (e. g., Bond, Fliedner and Archambeau, 1965). Compari- son of experimental data reveals considerable variations in LDSD values even after total-body irradiation with conventional X rays, ranging from 4 to 6 Gy in the monkey, 7.1 to 9 Gy in the rat and from 6.4 to 9 Gy in the mouse (see also Hall, 1978). Part of the discrepancy in the LDso values can possibly be attributed to inadequacies in the dosimetry procedures and exposure arrangements employed. As far as clinical experience is concerned, there is now an appreciable amount of information available about the effect of total- body irradiation as a conditioning treatment for bone marrow transplan- tation in patients suffering from leukaemia or aplastic anaemia. The results from different centres, including the incidence of complications such as radiation pneumonitis, are considerably different. This can part I y be connected with the application of different radiation sched- ules: large single dose versus fractionated or protracted irradiation.

There are two important reasons for commencing this new series of publi cations entitled "Advances and Technical Standards in Neurosurgery" 1. the lack of any organized common European postgraduate training system for young neurosurgeons and 2. the language barriers, which impede the exchange of neuro surgical findings in Europe more than in other parts of the world. The fact that the English language is well on the way to becoming the international medium at European scientific conferences is a great asset in terms of mutual understanding. Therefore the Editors have decided to publish all contributions in English, regardless of the native language of the authors. All contributions are submitted to the entire editorial board before publi cation of any volume. Our series is not intended to compete with the publications of original scientific papers in other neurosurgical journals. Our intention is, rather, to present fields of neurosurgery and related areas in which important recent advances have been made. The contributions will be written by specialists in the given fields and will constitute the first part of each volume."

There have been significant advances in the treatment of sarcomas in the past several years. Further, different clini cal treatment programs are being advocated in different areas including surgery alone, surgery with preoperative or post operative chemotherapy, surgery with different radiotherapy modalities, with each investigator espousing his own treat ment program. On the other side, there is the question of whether these treatment programs are offering better results or whether the natural history of sarcomas has changed. The International Symposium on Sarcomas was held at Innisbrook Resort, Tarpon Springs, Florida, October 8-10, 1987. This was the first international symposium to date involving all of the disciplines treating sarcomas including pathologists, orthopaedic surgeons, general surgeons, medical oncologists, pediatric oncologists, and radiation oncol ogists. The Symposium brought together a number of special ists working in the clinical field of sarcomas for a presen tation of their specific treatment programs and their results. The presentations were followed by panel discussions to stimulate educational debate as to the different forms of treatment for sarcomas and to formulate some conformity in control of disease, control of spread, and ultimate function for the patient. James R. Ryan, M.D."

Interest in bone densitometry methods has recently experienced a resurgence within the medical community. Physicians have become more interested than ever before in the diagnosis and treatment of degenerative diseases of bone such as osteoporosis. The public perception of osteoporosis and its prevention has been recently heightened. Because osteoporosis is widespread, especially in women, and leads to an increase in fractures in our population, many re searchers and clinicians are strongly motivated in their search for more sensi tive and accurate methods of diagnosis. This book was written for physicians, scientists, engineers, medical phy sicists, and others desiring an introduction or further understanding of this exciting field. Beginning with the early development of x-ray film methods for assessing bone status, the field has steadily grown throughout the years. Novel and interesting devices have been designed for the measurement of bone mass, bone density, cortical thickness, and other parameters of bone changes. Both qualitative and quantitative bone methods are described. The techniques include imaging devices such as CT and radiography as well as fixed point methods in which bone characteristics of a region of interest are analyzed."

As an addition to the European postgraduate training system for young neurosurgeons we began to publish in 1974 this series devoted to Advances and Technical Standards in Neurosurgery which was later sponsored by the European Association of Neurosurgical Societies. The fact that the English language is well on the way to becoming the international medium at European scientific conferences is a great asset in terms of mutual understanding. Therefore we have decided to publish all contributions in English, regardless of the native language of the authors. All contributions are submitted to the entire editorial board before publication of any volume. is not intended to compete with the publications of original Our series scientific papers in other neurosurgical journals. Our intention is, rather, to present fields of neurosurgery and related areas in which important recent advances have been made. The contributions are written by specialists in the given fields and constitute the first part of each volume. In the second part of each volume, we publish detailed descriptions of standard operative procedures, furnished by experienced clinicians; in these articles the authors describe the techniques they employ and explain the advantages, difficulties and risks involved in the various procedures. This part is intended primarily to assist young neurosurgeons in their post graduate training. However, we are convinced that it will also be useful to experienced, fully trained neurosurgeons."

As an addition to the European postgraduate training system for young neurosurgeons we began to publish in 1974 this series devoted to Advances and Technical Standards in Neurosurgery which was later sponsored by the Euro pean Association of Neurosurgical Societies. The fact that the English language is well on the way to becoming the international medium at European scientific conferences is a great asset in terms of mutual understanding. Therefore we have decided to publish all contributions in English, regardless of the native language of the authors. All contributions are submitted to the entire editorial board before publication of any volume. Our series is not intended to compete with the publications of original scientific papers in other neurosurgical journals. Our intention is, rather, to present fields of neurosurgery and related areas in which important recent advances have been made. The contributions are written by specialists in the given fields and constitute the first part of each volume. In the second part of each volume, we publish detailed descriptions of standard operative procedures, furnished by experienced clinicians; in these articles the authors describe the techniques they employ and explain the advantages, difficulties and risks involved in the various procedures. This part is intended primarily to assist young neurosurgeons in their postgraduate training. However, we are convinced that it will also be useful to experienced, fully trained neurosurgeons."

The rapid growth of fibre-optic endoscopy in recent than 7,500 examinations has been accumulated. years has had two consequences for the radiology of In part I of this study the theoretical background the stomach and the duocienum. and the technique of examination proper are de- scribed. The basic principles of interpretation of DC 1. Radiology has lost its previously rather auton- studies are stated. omous position in this field. Part II deals with the results. Chapter 5 consists of 2. As a result of the constant feed-back from the general remarks on the results, and on the comple- endoscopist, which the radiologist can and should mentary role of radiological examination and endos- have, he is in an excellent position to re-evaluate copy. Chapter 6 deals with a quantative study of and improve his own technique of examination. standard biphasic-contrast examinations in patients The author believes that the radiological exam- over a period of 3 years. This study was restricted to ination retains its value as a screening technique and malignant lesions, because it is only in this group a complementary method to gastroscopy and biop- that the definite criterion, a histological diagnosis, is sy. Only a sophisticated radiological technique will obtained. The natural history of malignant lesions fulfil these requirements. In 1973 the author devel- also makes follow-up studies possible. Results of the oped a standard examination that was called "bi- diagnosis of Early Gastric Cancer (EGC) are phasic", because it combines the advantages of included.

It Itis is 1984, 1984, a a year year immortalized immortalizedby by George GeorgeOrwell Orwell some some35 35 year year ago. ago. In In 1949, 1949, he he prophesized prophesized a a world worlddominated dominated by by television television images images and andelectronic electronic communica communica tions. Orwell's vision of an incredible technologic revolution is the reality of the tions. Orwell'svisionofanincredibletechnologicrevolutionistherealityofthe 1980's. 1980's. Over Over the the past past three threedecades, decades, this this technical technicalexplosion explosion has has impacted impacted on on all all levels levelsof of society, society, including including the the practice practice of ofMedicine. Medicine. In 1949, the cardiologist had available to him only his stethoscope, the chest In1949, thecardiologisthadavailabletohimonlyhisstethoscope, thechest roentgenogram, roentgenogram, the theelectrocardiogram, electrocardiogram, and and his hisclinical clinical astuteness. astuteness. In In 1984, 1984, the the cardiologist still requires great clinical skills, but also has available to him echo cardiologiststillrequiresgreatclinicalskills, butalsohasavailabletohimecho cardiography, cardiography, radionuclide radionuclideperfusion perfusion and and functional functional tests, tests, digital digital radiography, radiography, computed computed tomography, tomography, positron positronemission emission tomography, tomography, and and nuclear nuclearmagnetic magnetic resonance resonanceimaging. imaging. These These imaging imagingmodalities modalities are are the theresult result of ofthe the development developmentof of the the digital digitalcomputer, computer, and and the theexplosive explosive advances advances in in microelectronics. microelectronics. Cardiac Cardiac imaging imaginghas has rapidly rapidlyevolved evolved into intoa a specialized specialized area area of of interest interestshared shared by by cardiolo cardiolo gists, radiologists, engineers, physicists, and statisticians. Our book, Digital gists, radiologists, engineers, physicists, andstatisticians."

As an addition to the European postgraduate training system for young neurosurgeons we began to publish in 1974 this series devoted to Advances and Technical Standards in Neurosurgery which was later sponsored by the European Association of Neurosurgical Societies. The fact that the English language is well on the way to becoming the international medium at European scientific conferences is a great asset in terms of mutual understanding. Therefore we have decided to publish all contributions in English, regardless of the native language of the authors. All contributions are submitted to the entire editorial board before publication of any volume. Our series is not intended to compete with the publications of original scientific papers in other neurosurgical journals. Our intention is, rather, to present fields of neurosurgery and related areas in which important recent advances have been made. The contributions are written by specialists in the given fields and constitute the first part of each volume. In the second part of each volume, we publish detailed descriptions Of standard operative procedures, furnished by experienced clinicians; in these articles the authors describe the techniques they employ and explain the advantages, difficulties and risks involved in the various procedures. This part is intended primarily to assist young neurosurgeons in their post graduate training. However, we are convinced that it will also be useful to experienced, fully trained neurosurgeons."