title: Intraperitoneal versus retroperitoneal air signs in abdominal radiographs.
authors.forename: Yen-Chieh
authors.initials: YC
authors.lastname: Wang
authors.forename: Chih-Ming
authors.initials: CM
authors.lastname: Lin
authors.forename: Shao-Kuan
authors.initials: SK
authors.lastname: Chen
mesh_terms: D000006:Abdomen, Acute / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D000368:Aged; D005260:Female; D006801:Humans; D010439:Peptic Ulcer Perforation / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D011027:Pneumoperitoneum / Q000145:classification / Q000000981:diagnostic imaging* / Q000209:etiology; D011704:Pyelonephritis / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D011859:Radiography