[Role of ultrasound in children with emergency gastrointestinal diseases].

Over the last twenty years, ultrasound has progressively become the primary modality used to assess the acute pediatric abdomen. The lack of radiation exposure and the high diagnostic efficacy of US have contributed to broaden the use of US. During his career, any radiologist may be involved in the evaluation of an acute abdomen in a child. He has to be familiar with the sonographic findings and the age-related symptoms which allow diagnosis of intussusception, hypertrophic pyloric stenosis, midgut volvulus, and appendicitis. He also has to be familiar with the findings which help to exclude these diseases. For experienced radiologists the accuracy in detecting appendicitis and intussusception are respectively close to 95% and 100%. In this chapter, we will also discuss the differential diagnoses of the most frequent causes of acute pediatric abdomen and the technical limitations of US. The learning objectives will be