Both of us were lucky indeed to have our research associate, Dr. Yvonne H oogeveen, to keep us on course and spend much time and effort on getting the text in optimal shape. Without her, it would have been dif? cult, if not imp- sible, to ensure the completion of this endeavour. To complicate matters further, we had a number of potential and agreed authors either dropping out due to illness or because of changes in empl- ment situations precluding them from contributing. Nevertheless, the result is a truly international effort that we are proud of. For this we wish to thank the co-workers of Springer-Verlag, as they were truly exemplary in their cooperation. Ursula Davis, in particular, deserves our thanks. Dr. Devos and I are extremely thankful to all the authors: you all are the book! They were selected for their prominence in their specialty, and the list of these authors represents a broad combination of experience, teaching ability and stature. Finally, it was a pleasure to contribute to better imaging in children, so- thing that pediatric radiologists of course have made their aim in life, but also should be aimed for by all radiologists in general.