Marcelle Megret has assembled a comprehensive collection of radiographie images during her work in the field of com puted tomography of the cranial skeleton. This collection and her experience have made it possible for her to prepare these exercises in radiological diagnosis concerned exclusively with craniofacial tomodensitometry. The viewer will appreciate the choice of original docu ments of the highest quality, and also note the delicacy of execution of the diagrams, all drawn by the author herself. Marcelle Megret, like most of my students, conceives and carries out the schematas herself. The requirements concern ing certainty, strictness, precision, and objectivity would lead her to agree with Ludwig Wittgenstein's observations that since certain things cannot be said they must be shown, and that rules are insufficient when there are no examples. I should like this book to be successful. It inaugurates Marcelle Megret's career as an author and is an honor to the University of Geneva.

This book gets to the heart of what radiology is and what radiologists do. As a relatively young speciality, there is no guide for radiologists to act as a moral compass. Until now, that is. You will not find any dry technical matters in here. You will not find any clues about how to interpret images better. This book details the 'other 50%': the rest of the working week when a radiologist is not reading scans or performing procedures. The essence of radiology is distilled and offered up to the reader. If you want a comfortable read that offers bland reassurances, look elsewhere. If you want a book that questions everything and discusses uncomfortable truths, this is the book for you. Each of the Rules addresses an important part of professional practice. This book is a manifesto for all radiologists across the globe to raise their game, to be more effective and to serve their patients better.

The first MATLAB (R) programming book written specifically for clinical radiotherapy medical physicists and medical physics trainees, this much-needed book teaches users how to create their own clinical applications using MATLAB (R), as a complement to commercial software particularly when the latter does not cover specific local clinical needs. Chapters explore key radiotherapy areas such as handling volumes, 3D dose calculation, comparing dose distributions, reconstructing treatment plans and their summations, and automated tests for machine quality assurance. Readers will learn to independently analyse and process images, doses, structures, and other radiotherapy clinical data to deal with standard and non-standard situations in radiotherapy. This book will also significantly improve understanding of areas such as data nature, information content, DICOM RT standard, and data flow. It will be an invaluable reference for students of medical physics, in addition to clinical radiotherapy physicists and researchers working in radiotherapy. Features: Includes real clinical medical physics applications derived from actual clinical problems Provides commented MATLAB (R) scripts working with sample data and/or own data matching input requirements Promotes critical thinking and practical problem solving skills

Like my first book of exercises in radiological diagnosis con- cerning the vertebrae in adults, the first part of this book consists of an atlas of images ready for immanent reading. The images are numbered, each number corresponding to a case. The second part comprises the corresponding comments, critical interpretations, and drawings (using the same num- bers as the corresponding radiographs in the first part). I hope that this second booklet will be as appreciated as was the first, which was published in four languages (Radio- diagnosis of the Vertebrae in Adults. Springer, Berlin Hei- delberg New York 1983). My own documentation having proved deficient in some fields, I had recourse to the didactic collections oimy collea- gues, friends, and students. Special thanks are due to Prof. J. F. Bonneville, and to Drs. J. L. Dietemann, Y. Dirheimer, J. C. Dosch, and J. Vignaud. AUGUSTE WACKENHEIM VII Contents Introduction ...1 Part One: Iconography 5 Part Two: Commentary with Corresponding Schemata. 107 References . . 189 Subject Index 191 IX Introduction The analysis or the reading of an X-ray picture proceeds from struc- turalistic rules, such as the immanence, the synchronism, the significa- tion (signifiant and signifie of a sign), first from the semeiologic and then from the semantic point of view. In a simpler way, one can say that it is necessary to distinguish the signifiant, the signiGBPie, the comment, the interpretation, and the radiobioclinical confrontation. The signifiant or character is a normal or pathological "characteris- tic" part of the image.

This volume is the latest in the series Exercises in Radio logical Diagnosis, launched by the Strasbourg School of Radio logy. Further volumes on the facial bones, senology, and abdominal tomography are in preparation. Jean-Louis Dietemann has over a decade's experience of radiodiagnosis of the skull, and has already proven his talents as a teacher with his earlier books on the sella turcica and on carotid angiography. The present volume will assuredly be a great success and will enhance the series. Professor A. W ACKENHEIM Hospices Civils de Strasbourg Centre Hospitalier Regional Service de Radiologie I Strasbourg v Contents Part One: Iconography . . . . . . . . . . . . .. . . 1 . Part Two: Commentary with Corresponding Schemata. 85 References . . 165 Subject Index 167 VII Part One Iconography 1 1 a b 3 2 a b 4 3 4 5 6 6 a b 7 7 8 8 a b 9 9 10 10 11 a b 11 12 13 a b 13 a b 14 b 15 16 17 16 17 20 18 21 a b 19 22 a b 20 21 24 a b 22 b 23 26 27 24 a 25 26 29 27 31 32 28 33 34 29 35 36 30 37 a b 31 38 39 32 40 41 33 42 43 34 44 a b 35 44 c 45 a 36 45 b ~----~------~~ c 37 46 47 38 48 49 39 50 a b 40 41 52 53 a 42 53 b 54 a 43 54 b 55 44 56

This book contains the contributions to the symposium "Functional Mapping of the Brain in Vascular Disorders", held at the Thirteenth World Congress of Neurology, Sep- tember 1-6, 1985 in Hamburg, FRG. I have to thank the contributors to this symposium for submitting their manu- scripts long before the congress so that the printed procee- dings could be distributed to the audience. I hope that this will enable the participants in this symposium not only to recall the vivid presentation of the lectures and the highlights of the discussions, but also to widen their knowlegde of the topics dealt with during the symposium by rereading the chapters on the various issues. I would also like to express my thanks to the company UCB, Kerpen, FRG, who sup- ported the symposium and the printing of these proceedings. W. -D. HEISS Cologne, July 1985 Contents The Purpose of Functional Mapping in Focal Cerebral Ischemia W. -D. Heiss ...1 Positron Emission Tomography Versus Nuclear Magnetic Resonance Imaging? M. M. Ter-Pogossian (With 1 Figure) ...5 Aims on Phosphorus-3l Magnetic Resonance Imaging K. Kogure, H. Ohtomo, S. Matsui, and H. Kohno (With 10 Figures) ...1 5 In Vivo Nuclear Magnetic Resonance Imaging of Sodium-23 in the Human Head S. K. Hilal, A. A. Maudsley, J. B. Ra, H. E. Simon, P. Roschmann, S. Wittekoek, Z. H. Cho, and S. K. Mun (With 5 Figures) ...29 Uncoupling of Flow and Metabolism in Infarcted Tissue T. Jones, R. J. S. Wise, R. S. J. Frackowiak, J. M.

The anterior inferior cerebellar artery (AI CA) is one of the major branches of the basilar artery and supplies part of the pons, the upper medulla, and the cerebellar hemisphere. The artery can be visualized by means of vertebral angiography. This technique of examination was carried out for the first time in 1933 by Moniz and co-workers (Moniz and Alves 1933, Moniz et al. 1933). During the decades that followed, angiographic techniques improved considera bly, with the result that more details of the angioarchitecture of the posterior cranial fossa could be demonstrated. Satisfactory visualization of the AICA and its branches depends greatly on the use of subtraction, and this is the reason why detailed reports on the angiographic appearance of the artery were for the greater part published after 1965, when subtraction techniques were more consistently used (Takahashi et al. 1968, 1974; Gerald et al. 1973). The angiographic appearance of the various segments of the AICA in the lateral projection, both in the normal situation and in the presence of tumors, has been studied by Naidich et al. (1976a, b). The primary aim was to recognize and denominate the separate branches, loops, and segments of the AICA in order to locate tumors on the basis of displacements of portions of the artery. The fact that the course, caliber, and distribution of the AICA are very variable was not emphasized."

Even the earliest applications of nuclear magnetic resonance (NMR) spectroscopy and tomography to medical inquiries, using experimental apparatus that was primitive by today's standards, demonstrated the extraordinary potential of the NMR method. The subsequent rapid advances in this area were due largely to the ef forts of commercial manufacturers, who, by improving magnet and computer designs, were able to produce and market instruments having a remarkable image quality. Experimental data from the ftrst systematic studies on the medical uses of NMR leave little doubt that NMR will gain a permanent place in clinical diagnosis. The clinician, then, is confronted with an entirely new diagnostic modality. Because NMR has been used extensively in chemistry and physics for years, a great many textbooks are already available on the subject. However, the majority of these have been written for the natural scientist who is well versed in mathematics and physics. Assumptions are made and terms are used that would not be appro priate for a medical or biochemical text. The goal of this introduc tion, therefore, is to discuss the principles of the NMR technique in terms that are meaningful to the medical student and medical pro fessional.

Local interstitial radiation therapy of intrinsic and inaccessible brain tumors is confronted with two major problems: 1. The tolerance of normal brain tissue, which is usually involved in local tumor irradiation, i.e. perifocal white matter edema and demyelinating effects, is crucial. 2. Data on radiation effects of implanted radioactive sources on neoplastic tissue, i.e. data on the radiosensitivity and on the biology of tumors, are still widely unavailable. In clinical practice the dose with which to achieve a given volume of tumor necrosis is roughly estimated. This report deals with the experimental findings of Iodine-125 and Iridium-I92 permanent implants in healthy and neoplastic brain tissue. Our own experimental findings are correlated with experimental data on Yttnul11-l)O irradiation from the literature. The study is directed to collect data on the tolerance non-tumoral brain tissue and to attempt to establish a dose-response relationship. Morphologic Changes in the Dog Brain Following Interstitial Iodine-125 Irradiation Iodine-I25 seeds (manufactured by 3 M Company, St. Paul, M. N.) with an activity of 3.55 mCi were permanently implanted under stereotactic conditions into the subcortical white matter of the gyrus coronalis of the left hemisphere in 6 beagle dogs. One animal with a non-radioactive seed implanted under similar operative conditions served as a control. The animals were allowed to survive 25, 46, 71, 94, 248, 368 days, respectively, after the implantation. The control animal survived 46 days. A detailed description of the experimental procedure is given elsewhere 16. 17.

The International Symposium on Positron Emission Tomography of the Brain was held at Schloss Auel in Lohmar, near Cologne, FRG, on May 3rd to 8th, 1982. This isolated place was chosen to bring together and keep together people active in research employing PET. The partic ipants were asked to report their ongoing work, to discuss upcoming problems, and to indicate future developments. In contrast to the large international meetings which suffer from lack of time for discussion and are affected by the distractions of major cities, our symposium provided ample opportunity for discussion during the scientific sessions and guaranteed a free exchange of ideas during the leisure time spent to gether. It also gave us the chance to celebrate the founding of a new Max Planck Institute for Neurological Research, whose two depart ments are headed by Dr. K. -A. Hossmann and myself, and to mark the start of positron emission tomography in our laboratory. The book contains the invited papers presented at the meeting and the formal minipapers given at the final general discussion, moderated su perbly by Dr. L. Sokoloff. In order to accelerate publication, the discus sions of the individual papers and the final discussion have been omit ted. However, every participant will remember the atmosphere and the highlights of the discussions, which gave a special character to the whole event."

In the past ten years, there have been significant advances in the diagnosis and therapy of arterial vascular disease. While long-term morbidity can only be improved by changing the patient's life-style and removing any risk factors that may be present(hypertension, hyperlipidemia, obesity, diabetesmellitus, nicotine abuse), symptomatic relief may be obtained by various procedures. Besides conservative treatment of arterial occlusive disease (physical therapy, medical treatment) and surgical vascular interventions (thromboendarterectomy, bypass procedures), balloon catheters introduced percutaneously under local anesthesia have found increased application in virtually all areas for the dilatation and recanalization of obstructive lesions in the past few years. The technique of balloon dilatation, as introduced by Griintzig as a further development of the percutaneous interventions by Dotter and Judkins, is no longer the decisive issue. The main objective of present clinical research is to de termine the proper indications and patient selection for this procedure, which has found its place between conservative treatment and surgery. The contents of this Symposium should provide some guidelines for the indi cations and postprocedural therapy for the referring physician, the angiologist, and for the radiologist and cardiologist performing the dilatation. We owe our thanks to all the specialists involved, who have provided us with the benefits of their experience. Mrs. H. Beilmann and Dr. M. Wojtowycz con tributed substantially to the preparation of the text. I would like to thank them and the staff of Springer-Verlag for their conscientious work in the interest of composition and publication quality."

Our pocket-book has come about as a direct attempt to answer the needs of our clinical students. We have tried to use radiology as a magic window for looking at their patients' medical and surgical problems. The book is very simple and highly selective. A number of excellent introductory texts already exist for students seeking comprehensive and balanced accounts of radiology as a specialty. We have tried to keep close to our title: a good guide shows you a bare outline of where you might go, and makes sure you see the highlights. He will point to interesting places that deserve study, without going into them himself. Occasionally he may enlarge on a topic when the information is not readily available anywhere else (as in our chapter on the skull). And he will be ready to listen to students asking, perhaps rather shyly, some basic questions (as in our first and last chapters). We have taken Voltaire as our own guide: "Le secret d'ennuyer est . . . de tout dire." The book has been written by only a small group of all those teaching radiology at Cambridge. We wish to absolve our colleagues from all blame, and to thank them for generous support, especially in the loan of illustrations. Cambridge, 1982 Thomas Sherwood Contents 1. Introduction: Medicine and Radiology Thomas Sherwood. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2. Diagnosis Thomas Sherwood. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Looking at an x-ray. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Diagnostic pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Sensitivity and specificity of tests . . . . . . . . . . . . . . . . . . . . . 14 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3. Bones Thomas Sherwood. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

This book is intended for beginners and for those who want to refresh their knowledge of the elementary radioanatomy of the vertebrae, particularly their pathological radioanatomy. I do not pretend, as does Roger Martin du Gard's hero, that one always must begin with a radiographic examination, but I do believe that a student, especially one interested in radiology, must be able to apprehend an image isolated from its clinical context. To optimize memorization of the image I have selected unmistakable cases with marked, well-evolved lesions. This will enable the studentlater to recognize less distinct images of the same kind. The first section of the book is exclusively iconographic. After studying an image, the reader will find in the second section, under the appropriate reference number, a commen tary illustrated with a realistic drawing by my friend Dr. Csaba Hethalmi. Attention to the following points will assist a fruitful reading: 1. Cases 1-5 involve normal subjects; all other cases are pathological. 2. The reader must imagine that he is conducting a routine examination and draw on his resources to make a practical analysis of an image. As a matter of fact, all the films (except that in case 46, which is the radiograph of a specimen) were -indeed taken under routine conditions using standard pro jections. 3. The cases are in no systematic or nosological order. Each case is illustrated with one, two, or (rarely) three images.

The technology of automatic pattern recognition and digital image processing, after over two decades of basic research, is now appearing in important applications in biology and medicine as weIl as industrial, military and aerospace systems. In response to a suggestion from Mr. Norman Caplan, *the Program Director for Automation, Bioengineering and Sensing at the United States National Science Foundation, the authors of this book organized the first Uni ted States-France Seminar on Biomedical Image Processing. The seminar met at the Hotel Beau Site, St. Pierre de Chartreuse, France on May 27-31, 1980. This book contains most of the papers presented at this seminar, as weIl as two papers (by Bisconte et al. and by Ploem ~ al.) discussed at the seminar but not appearing on the program. We view the subject matter of this seminar as a confluence amon~ three broad scientific and engineering disciplines: 1) biology and medicine, 2) imaging and optics, and 3) computer science and computer engineering. The seminar had three objectives: 1) to discuss the state of the art of biomedical image processing with emphasis on four themes: microscopic image analysis, radiological image analysis, tomography, and image processing technology; 2) to place values on directions for future research so as to give guidance to agencies supporting such research; and 3) to explore and encourage various areas of cooperative research between French and Uni ted States scientists within the field of Biomedical Image Processing.

W.DRIESEN This volume contains the original text of 60 papers delivered at the 32nd Annual Meeting of the German Society for Neurosurgery, held in TUbingen, 22nd to 25th April, 1981. They represent a selection from 91 papers submitted, a third of which had to be excluded on critical analysis. This was deemed necessary on account of costs, and in order to keep the volume of a size and standard usually achieved within the last few years. Three main subjects were considered: 1. changes in methods of investigation and treatment of neurosurgi cal.conditions, brought about by the use of computerised axial tomography (C.A.T . scanning); 2. papers dealing with fundamental research concerned with normal and abnormal cerebral metabolism; 3. trauma to the vertebral column and spinal cord, and its sequelae; and, 4. free communications. The organisers of this meeting tried, in contradistinction to pre vious custom, to shift the emphasis away from highlighting major communications, and so to remain true to their intention to allow experts in their fields to introduce their subjects and pin-point problems, to which subsequent speakers could then address them selves in detail in their own papers. In my view, this did occur in a meaningful way, although not to perfection; a goal always difficult to attain."

In diagnostic medicine a large part of information about the patient is drawn from data, which, more or less, are represented in an opti calor pictorial form. There is a very wide range of such data as e.g. the patients appearance, the various kinds of radiological images, or cytological imagery. In conventional diagnostics the data, as it comes from the acquisition device, is perceived by the physician and is interpreted with the help of a large amount of "a priori" knowledge to give a diagnostic finding. During the last 15 years a steadily rising number of attempts have been made to support these processes by the application of com puters. The attempts mainly concentrate on three objectives: 1. Support of the perception process by the production of better or new types of images, e.g. by Computer tomography or Computer angio graphy (image processing) . 2. Automation of the interpretation process, e.g. for bloodcell dif ferentiation (pattern recognition) . 3. Management of the steeply rising amount of medical image data in the hospital (image data bases) . Although the early applications of digital methods aimed at the second . . objective, in the last years much more success has been a achieved in the support of the perception process by methods of image process ing. The reason for this is obvious - in the case of automatic interpre tation the a priori knowledge of the physician has to be formalized.

Applications of angiography have expanded to include not only diagnostic proce- dures but also therapeutic interventions. The introduction of regional administra- tion of vasoactive drugs through percutaneously placed angiographic catheters was soon followed by methods of transcatheter vessel occlusion using temporary or permanent embolic materials. At the same time methods of opening up nar- rowed or completely obstructed blood vessels with percutaneously introduced balloon catheters were being perfected. Thus, regional blood flow reduction or regional blood flow increase can now be accomplished with percutaneous angiographic methods in lieu of major surgical interventions. The advantages in terms of reduced morbidity, length of hospital stay and cost are evident. Therapeutic angiography is a rapidly advancing and therefore changing field. This monograph aims at capturing some of the most recent advances and also at presenting some of the controversies. In order to accomplish this task the editors invited a selected group of cardiovascular radiologists, to contribute in their respective fields of therapeutic angiography. For a balanced view other experts - usually nonradiologists - were also asked to present their views, com- ments, and criticisms. Whenever opinions were far apart an opportunity was given for reply or rebuttal. Thus, up-to-date information with supporting or oppos- ing expert views is presented on the topics of transluminal angioplasty, transcath- eter vessel occlusion, regional drug infusions, and radiologic interventions in thromboembolic disease.

This book is a volume in the Penn Press Anniversary Collection. To mark its 125th anniversary in 2015, the University of Pennsylvania Press rereleased more than 1,100 titles from Penn Press's distinguished backlist from 1899-1999 that had fallen out of print. Spanning an entire century, the Anniversary Collection offers peer-reviewed scholarship in a wide range of subject areas.

G. T. Herman F. Natterer Universitat des Saarlandes Medical Image Processing Group Department of Computer Science Angewandte Mathematik und State University of New York at Informatik 66 Saarbrucken Buffalo Germany 4226 Ridge Lea Road Amherst, N. Y. 14226 USA In August 1978 we have attended a working conference on Computer Aided Tomography and Ultrasonics in Medicine which was held in Haifa, Israel under the auspices of the International Federation for Information Pro- cessing [1]. That meeting, in common with other meetings relating to computerized tomography, concentrated on the physical, engineering and clinical aspects of the topic, with little attention paid to the under- lying mathematics, and no attention paid to recent developments in ma- thematics inspired by computerized tomography (although not necessarily) useful for computerized tomography). We both felt that it would be worthwhile to organize a meeting of mathematicians which would concen- trate on the mathematical aspects of computerized tomography. This vol- ume (and the meeting on which it is based) is the outcome of our decision in August 1978 to attempt to bring together such a meeting. In the meantime much has been published on the topic of computerized to- mography.

The acute abdomen often perplexes the expert as well as the young physician. There are few areas in medicine in which Hippocrates' aphorism-the art is long, life is short, decision difficult, and delay perilous-is more applicable than here. Too often the harried physician fails to listen to the patient who is trying desperately to suggest the diagnosis. The significance of various types and location of pain often are neglected by the doctor. Physical findings are influenced by experience; the presence or absence of tenderness or a mass may be answered in entirely different ways by various observers. Because solid facts frequently are lacking, attempts to resolve diagnostic dilemmas by computer analysis or by algorithms are not likely to be successful. Fortunately, in the great majority of cases, unusual and difficult diagnostic procedures are not necessary for the identification of the acute abdomen and of the major disease. Astute clinical judgment must be based primarily upon careful attention to the pa tient's words and detailed observation."

Radiotherapy using fast electrons, whether alone or in combination with high-voltage, has met with increasing interest in the last few years. This book provides a useful account of the present state of knowledge and critically discusses where an improvement of results is certain or prob able - in contrast to results with radiotherapy using photons alone. The work also considers additional improvements which might be expected to accrue from past experience and particular attention is paid to the nature and possible dangers of electron therapy. Bern, August 1980 A. Zuppinger Contents Opening Address A. Zuppinger . . . . . . . . . . . . . . . . . . . . . . ........... . . . . . . . . . . Physical Section Introduction J .L. Minchole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Computer Treatment Planning of Lung Radiation by Means of High Energy Electrons G. Poretti, F. Ionesco-Farca, and P. Veraguth. . . . . . . . . . . . . . . . . . . . . . 6 Electron Beam Quality Parameters and Absorbed Dose Distributions from Therapy Accelerators A. Brahme and H. Svensson. . . . . . . . . . . . . . . . . . . . . . . . . . . 12 . . . . . . . Surface Dose in Electron Beams and Association with High Energy X-Ray Beams J.C. Ro senwald. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 . . . . . . . . . . Electronic Wedge Filter for the Asklepitron 45 R. Hilnig, A.v.Arx, and A. Scholz. . . . . . . . . . . . . . . . . . . . . . . . 25 . . . . . . Magnetic Field Modification of Electron Beam Dose Distributions in Inhomogeneous Media B.R. Paliwal and A.L. Wiley, Jr. . . . . . . . . . . . . . . . . . . . . . . . . 28 . . . . . . . Conclusions of the Physical Section J.C. Rosenwald. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 . . . . . . . . . . Clinical Section Clinical Radiobiology A. Zuppinger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 . . . . . . . . . . Indications for Electron Beam Therapy J.P.Bataini ............................................ 37 Contents VIII The Electron Beam Therapy for Malignant Tumors: Indications and Limitations E. Scherer and M. Bamberg. . . . . . . . . . . . . . . . . . . . . . . . . . . 39 . . . . . . . Electron Therapy for Cutaneous Epitheliomas H. Pourquier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 . . . . . . . . . ."

The imaging aspects of radiography have undergone con many sources and was in general freely given when requested siderable change in the last few years and as a teacher of and this is gratefully acknowledged. In particular I would radiography for many years I have often noticed the lack of a like to express my sincere thanks for help and information to comprehensive reference book for students. This book is an Mr J. Day of DuPont (UK) Ltd. particularly for the infor attempt to correct that situation and I hope this text will be mation and illustrations in the chapter on automated film of value not only to student radiographers but also prac handling; Mr D. Harper and Mr R. Black of Kodak Ltd.; tising radiographers as well. Fujimex Ltd.; CEA of Sweden; 3M (UK) Ltd.; Wardray Much of the information is based on personal experiment Products Ltd.; D. A. Pitman Ltd.; Agfa-Gevaert; PSR Ltd. and the knowledge gained of students' difficulties in studying for their help with information on silver recovery, and this subject. I have attempted to gather together in one book Radiatron Ltd. for their help with safelighting. All were most all the information required to understand the fundamentals helpful in my many requests for information. of the subject both for examination and for practice. Some To Mrs A. Dalton and Mrs P."

Of the joints of the body commonly afflicted by serious pathology the knee is the most accessible. Because it is so accessible drastic treatment may be undertaken prematurely and incorrectly. This does not threaten life but may cause permanent morbidity. Dr Stoker has set about examining this joint in depth as a radiologist. As a direct result the surgeon will be helped to make a correct diagnosis and avoid pitfalls, by a diagnostic procedure that is of little inconvenience to a patient. Arthrography is not new but a fresh appraisal is timely. This is not to suggest that there can be any slackening in clinical examination, or that other methods of examination do not have a place. But there are knee joint problems, particularly in teenage girls, in which a clinical diagnosis is very difficult, but must be made exactly. Arthrography must be accepted as a very useful method of examination of the knee joint and an essential one in certain circumstances. More radiologists should be interested in undertaking this examination and surgeons should ask for it. E.L. Trickey, F.R.C.S.