When retired it is a blessing if one has not become too tired by the strain of one's professional career. In the case of our retired engineer and scientist Rinus Vlaardingerbroek, however, this is not only a blessing for him person­ ally, but also a blessing for us in the field of Magnetic Resonance Imaging as he has chosen the theory of MRI to be the work-out exercise to keep himself in intellectual top condition. An exercise which has worked out very well and which has resulted in the consolidated and accessible form of the work of reference now in front of you. This work has become all the more lively and alive by illustrations with live images which have been added and analysed by clinical scientist Jacques den Boer. We at Philips Medical Systems feel proud of our comakership with the authors in their writing of this book. It demonstrates the value we share with them, which is "to achieve clinical superiority in MRI by quality and imagination" . During their careers Rinus Vlaardingerbroek and Jacques den Boer have made many contributions to the superiority of Philips MRI Systems. They have now bestowed us with a treasure offering benefits to the MRI community at large and thereby to health care in general: a much needed non-diffuse textbook to help further advance the diffusion of MRI.