Positron emission tomography (PET) has been at the forefront of fu- tional and molecular imaging for a number of years. The future of di- nostic imaging depends upon the ability to change from imaging anatomy to examining the processes at work in the body. The fact that there are now monographs examining particular aspects of PET, such as this book on the examination of children, speaks to the newly won maturity of PET. The authors are to be congratulated for the timely appearance of this volume. In recent years, PET has transformed the contributions of nuclear medicine to the diagnosis,...