This book, the seventh in the series Exercises in Radiological Diagnosis, deals with sonography, an imaging procedure in which the ability of the radiologist plays an exceptionally important role. The author, Catherine Roy, has very extensive experience in the clinical use of sonography. She has selected the images, which are of excellent quality, with great care to illustrate a wide range of conditions and has supplemented them by commentaries and discussions which are easy to comprehend. The systematic use of schematic drawings to interpret the images makes it possible for the reader to follow the author’s approach without any difficulty. Schematic drawings are par ticularly important in sonography because the relationship be tween the details in the images and the anatomy may be very weak. Images, schematic drawings, and text (both commentaries and interpretations) are three didactic elements which Cathe rine Roy has skill-fully combined in these exercises into an excellent whole. A. WACKENHEIM v Contents Introduction … … … … … … 1 Iconography, Commentary with Corresponding Schemata. . 2 Subject Index 203 VII Introduction Ultrasound imaging of the abdomen has now become a routine investi gation. It has brought about changes in the procedure of additional investigations and even rendered part of conventional radiology redun dant, particularly that concerning the bile ducts. These exercises are meant for students or physicians who already have basic knowledge of ultrasound diagnosis. It has not been possible to cover the entire spectrum of abdominal pathology, especially trauma, with 114 cases.