[Ultrasound study of "acute appendicitis," an elective procedure or obligation in general surgery. A prospective study].

576 patients admitted for suspected acute appendicitis were prospectively assessed by sonography following physical examination. The collective comprised - as proven by operation - 156 patients with acute appendicitis, 178 patients with chronic appendicitis or mesenteric lymphadenitis, as proven by observation, 186 patients suffering from gastroenteritis. 56 patients suffered from other diseases and 21 of them required urgent surgery. Based on clinical symptoms, correct diagnosis had been made in 433 patients (75%): gastroenteritis n = 186, chronic appendicitis or lymphadenitis n = 111 and acute appendicitis n = 136 (87%). In 123 patients the diagnosis was false positive, in 20 patients false negative. Based on sonographic assessment, 537 patients (93%) were correctly diagnosed; thus, in 129 patients (83%) an inflamed appendix was confirmed, in 56 patients; diagnosis of unrelated entities requiring urgent surgery correct in 21 cases. In 12 patients with mesenteric lymphadenitis - as proven by operation-a false positive, in another 27 patients with acute appendicitis a false negative diagnosis was made. The combination of clinical assessment and sonographic diagnosis yielded a correct diagnosis in 97% (560/576) comprising 414 true negative and 146 true positive results (94%) in respect of acute appendicitis.