title: Small bowel perforation resulting from blunt abdominal trauma: interval change of radiological characteristics.
abstract: OBJECTIVE
  We analyzed radiography and computed tomography (CT) findings of small bowel perforation due to blunt trauma to identify the keys to diagnosis.
  
  
  METHODS
  Twelve patients with surgically proven small bowel perforation were retrospectively studied. All patients underwent radiography and CT, and five underwent presurgical follow-up CT. Radiological findings were evaluated and correlated to the elapsed time from the onset of the trauma retrospectively.
  
  
  RESULTS
  Radiography demonstrated free air in only 8% (1/12) and 25% (3/12) at the initial and follow-up examinations, respectively. In contrast, the initial and follow-up CT scans detected extraluminal air in 58% (7/12) and 92% (11/12), respectively. Mesenteric fat obliteration was seen in 58% (7/12) and 75% (9/12) at initial and follow-up CT, respectively. The incidence of both extraluminal air and mesenteric fat obliteration on CT increased as time elapsed, particularly after 8 h. High-density ascites was seen in 75% at initial CT, including two patients without extraluminal air, but was observed in all but one patient at follow-up CT.
  
  
  CONCLUSIONS
  The chance of detecting extraluminal air increases as time elapses. High-density ascites may be seen without extraluminal air and might be an indirect or precedent sign of small bowel perforation. Radiologists need to be familiar with these radiological features.
authors.affiliation: Department of Radiology, Aso Iizuka Hospital, Iizuka, Fukuoka, Japan. sakum@fukuokae2.hosp.go.jp
authors.forename: Madoka
authors.initials: M
authors.lastname: Saku
authors.forename: Kengo
authors.initials: K
authors.lastname: Yoshimitsu
authors.forename: Junji
authors.initials: J
authors.lastname: Murakami
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Syuuiti
authors.initials: S
authors.lastname: Oguri
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Noguchi
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Ayukawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Honda
mesh_terms: D000007:Abdominal Injuries / Q000000981:diagnostic imaging; D000063:Accidents, Traffic; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007082:Ileum / Q000473:pathology*; D007416:Intestinal Perforation / Q000000981:diagnostic imaging* / Q000209:etiology; D007583:Jejunum / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011027:Pneumoperitoneum / Q000473:pathology; D011182:Postoperative Care; D011300:Preoperative Care; D011860:Radiography, Abdominal; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D015599:Trauma Severity Indices; D014949:Wounds, Nonpenetrating / Q000150:complications / Q000000981:diagnostic imaging*