During the 1970s ultrasonography developed along different paths in continental Eu­ rope and the English-speaking world. Whereas static imaging dominated the United Kingdom and North America, real-time examination performed by physicians was the norm in the Federal Republic of Germany and France. Francis Weill was uniquely able to bridge the gap between the two schools since he employed both techniques extensively. He made many important contributions to ab­ dominal ultrasonography during that decade, including the first descriptions of peri­ pancreatic vascular anatomy, the sonographic diagnostic features of obstructive jaun­ dice, and the localization of intraperitoneal fluid collections. During the past 20 years he has been working on an evolving textbook of gastroin­ testinal ultrasonography. This edition in English is the latest fruit of that effort. There are many textbooks of ultrasonography but very few are the work of a single author with a systematic, consistent, and thoroughly organized approach. Moreover, a work that has been crafted and refined by 20 years of clinical experience is certainly unique in this field. My relationship to this book began with the first English edition which I helped to translate from French. The current volume is a revised version of the most recent French edition, a book that we have found to be an invaluable reference in our de­ partment of radiological ultrasound for anyone who can manage a bit of French. I .