The urachus--an aid to the diagnosis of pneumoperitoneum.
D000368:Aged; D002988:Cloaca; D005260:Female; D006801:Humans; D011027:Pneumoperitoneum / Q000000981:diagnostic imaging*; D011187:Posture; D011859:Radiography; D014497:Urachus / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000196:embryology