This fourth edition of Understanding Radiography not only contains updated and refreshed material on familiar imaging technology, it also provides thorough explanations with many original illustrations of high speed CT imaging, PACS networks, computerized and direct digital radiography. Further, it contains new insights that will help prepare students for board exams. Experienced technologists will benefit through a broader understanding of the associated terminology, and how these technologies can be used to provide the highest level of imaging services possible. Chapters have undergone revision and new knowledge relating to equipment, methods, techniques and procedures have been assembled. Two chapters on PACS Network Imaging are included that cover the latest advanced technology for producing, storing and transmitting images, which will eventually replace conventional film methods in most facilities. Chapter objectives appear at the beginning of each chapter, and a set of study questions appear at the closing of each chapter that will help prepare students for registry exams. Experienced technologists will also benefit by gaining a broader understanding of how these advanced technologies can be used to provide the highest level of imaging services. As always, great care has been taken to provide a blend of the basic technical factors, their relationship to physics, and their applicability to typical situations with which the technologist will be confronted. Information on conventional imaging has also been expanded regarding tabular grain film and high frequency generators, radiation protection, x-ray tubes, and digital imaging. The nature of the radiographic image, film and processing, intensifying screens, focal distance, and the remnant beam are among the major subjects that are updated. Hundreds of drawings and radiographic reproductions are discussed throughout the book and many of these have been revised.