A thorough knowledge of normal radiological anatomy is necessary for detection and evaluation of pathological changes. In pediatric radiology, normal anatomy and normal proportions of anatomical structures may differ considerably from the adult, and may vary during growth. Therefore, in pediatric radiology there is a multitude of measurements, that in the individual patient is important, but that for the radiologist is not meaningful or even possible to keep in mind. This holds true both for the experienced pediatric radiologist, and for those who practise pediatric radiology only occasionally. This volume is written for both categories. In the literature, normal values are calculated and presented in many different ways, that are not always easy to compare, or easy to use in daily work. Therefore, we have revised and recalculated the data given by authors, in order to present the statistical upper and lower normal limits as between plus and minus two standard deviations (+/- 2SD). This means that about 2% of a normal population will be assessed as abnormally large and around 2% abnormally small with respect to the parameter assessed. In this way, the presentation throughout the book is uniform, and hopefully easy to use. All figures have been redrawn and computed in an attempt to make them as clear as possible.

During the last decade the therapeutic approach to musculoskeletal tumors has changed dramatically, from ablative surgery with ampu tation ofthe limb to reconstructive surgery with transplantation of bone and vessels combined with radio-and chemotherapy. This has changed the demands on radiologists and pathologists to a considerable degree. At the same time there has been a manifold increase in the diagnostic possibilities offered by modern radiology, with several new modalities affording a potential for morphologic depiction and tissue character ization that was unattainable a decade ago. Today, the definitive diagnostic work-up and treatment of patients with musculoskeletal tumors is most often done in tumor centers, by groups that ideally should be composed of an orthopedic surgeon, radiotherapist, oncologist, radiologist, pathologist and cytologist. It is necessary for all the members of this team to be well versed in the surgi cal and other treatment principles, in the pathologic concepts, and in the radiologic interpretation of musculoskeletal tumors. Moreover, it is important that the modern diagnostic approach to musculoskeletal tumors is well known also at the referring center, be it a private practi tioner's office or a large hospital. This will avoid unnecessary biopsies, and repetition of radiologic and other diagnostic procedures that have already been performed at the referring center."

WHO in collaboration with the International Commission for Radiologic Education (ICRE) of the International Society of Radiology (ISR) and the other members of the Global Steering Group for Education and Training in Diagnostic Imaging is creating a series of "Manuals of Diagnostic Imaging." The full series of manuals will primarily cover the examination techniques and interpretation of conventional diagnostic X-ray procedures. These manuals will replace and update the WHO Manual of Radiographic Interpretation for General Practitioners and the WHO Manual of Radiographic Technique.The present volume in this series, the manual Radiographic Anatomy and Interpretation of the Musculoskeletal System, provides an exhaustive description of radiographic normal anatomy as well as pathologic changes most frequently seen in musculoskeletal system including trauma, infections in bone and joints, metabolic, endocrine, and toxic disorders, tumours, congenital and developmental disorders. Backed by high-quality reproduction of radiographs, this manual will prove essential reading to general practitioners, medical specialists, radiographers and radiologists in any medical settings, although focusing specifically on needs in small and mid-size hospitals.