The Progress in Medical Radiation Physics series presents in-depth reviews of many of the significant developments resulting from the application of physics to medicine. This series is intended to span the gap between research papers published in scientific journals, which tend to lack details, and complete textbooks or theses, which are usually far more detailed than necessary to provide a working knowledge of the subject. Each chapter in this series is designed to provide just enough information to enable readers to both fully understand the development described and apply the technique or...