This book is based on a series of lectures given by an international team as part of a course on Bone Scintigraphy organized by the Boerhaave Committe for Postgraduate Medical Education (Leiden, January 1980). Bone scintigraphy and the use of radionuclide tracers in the investi­ gation of skeletal pathology has developed into a subject of its own. Significant advances in instrumentation, radiopharmaceuticals and data analysis has considerably widened the scope of clinical application. Beyond the important area of sensitive detection of malignant involve­ ment of the skeleton, major strides are being made in the investigation of benign bone disease and its metabolic aspects. The structure of this Boerhaave Course reflects this change, with considerable emphasis being given to the discussion of recent methods for tracer uptake quantitation, the discussion of inflammatory osseous disease, benign pathology in general and the investigation of metabolic bone disease. As a clinical tool, bone scintigraphy is present today in most if not all general and regional hospital institutions. It is a technique in demand by genera1 interns, surgeons, radiologists, paediatricians, oncologists and radiotherapists. New areas of application are being evaluated and to some extent consolidated. These include the difficult orthopaedic issues of bone avascularity, prosthesis loosening, infection and non-apparent fractures. A range of new techniques are available and applied to the follow-up of osteomalacia, osteoporosis, osteodystrophy and other con­ ditions where a more objective and even preferably a numerical approach is being explored.