Owing to the anatomic complexity of the neck and the diver sity of pathologic entities affecting it, the cervical region has long been of great semiological interest. Physical examination is an easy means of evaluating the size and origin of a solitary cervical mass, yet valid interpretation can prove difficult when the normal morphology of the neck has been altered; excellent examples are patients with extensive fibrosis or scarring secondary to previous irradiation or surgery. Like wise, physical examination cannot assess the relations of a pathologic process to adjacent structures - e. g., invasion can not be distinguished from simple displacement -and it is un suitable for monitoring therapeutic efficacy, such as the re sponse of metastatic nodes to medical management. Between physical examination, which remains fundamental, and exploratory surgical procedures, which are often the only means of obtaining indispensable anatomic proof for diagno sis, lie a number of recent imaging techniques including com puted tomography and magnetic resonance imaging using surface coils that provide invaluable information for the in vestigation of cervical pathologies. Real-time ultrasonogra phy occupies a privileged position because of its noninvasive ness, rapidity, and reliability, especially when performed by a specially trained examiner."

The aim of this work was not an exhaustive review of all pediatric echo graphic problems but a presentation of our daily experience with ultrasonography in pediatric practice. Several teams of pediatric radiologists from France and Belgium have combined their experiences to produce a practical book. The different authors have been chosen for their specific experience and their special area of work. The different chapters express therefore personal opinions. Unresolved questions are posed and ultrasonographic examinations are used in the diagnosis of different diseases, while the discoveries and ideas of the individual authors are described. Some fields are not included, such as echocardiography. Gabriel Kalifa Contents Chapter 1. Antenatal Diagnosis by Ultrasonography . . . . . . . . . . . . . . 1 . . . Introduction ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 Ultrasonography of a Normal Pregnancy ...................... 1 2.1 Timing of Successive Examinations. . . . . . . . . . . . . . . . . . . . . . . 1 2.2 Normal Fetal Anatomy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2.1 Central Nervous System .......................... 3 2.2.2 Chest........................................... 3 2.2.3 Abdomen....................................... 3 2.2.4 Skeletal System . . . . . . . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . .