title: Active extravasation of arterial contrast agent on post-traumatic abdominal computed tomography.
abstract: OBJECTIVE
  To evaluate the use of emergent dynamic intravenous contrast-enhanced computed tomography (CT) in the diagnosis of active arterial extravasation in patients admitted to hospital after blunt abdominal trauma.
  
  
  METHODS
  Four-hundred and ninety-eight consecutive emergent contrast-enhanced computed tomographic images of the abdomen and pelvis were retrospectively reviewed. The presence of and site(s) of active arterial extravasation were recorded. Two radiologists reviewed the images and compared the site(s) of extravasated arterial contrast agent with the site(s) of active hemorrhage established at angiography (n = 9) or surgery (n = 4).
  
  
  RESULTS
  Twenty-eight patients' computed tomographic images were identified as showing signs of extravasation of contrast agent representing active arterial bleeding. A total of 49 sources of active arterial extravasation were identified, 37 in 19 patients. A pelvic source of active arterial hemorrhage was most frequent and was typically associated with unstable pelvic fractures (n = 18). Other sources of active arterial hemorrhage included the liver (n = 3), spleen (n = 2), retroperitoneum (n = 1), kidney (n = 1), mesentery (n = 1), abdominal wall (n = 3) and lumbar region (n = 1). Only 9 of 28 patients became sufficiently hemodynamically unstable to warrant angiography. All 9 patients had a pelvic source of arterial extravasation on contrast-enhanced CT, and 7 demonstrated active bleeding requiring embolization. The contrast-enhanced computed tomographic images correctly indicated the anatomical source of bleeding in all 7 cases.
  
  
  CONCLUSIONS
  In patients who have experienced blunt abdominal trauma, attention should be paid to the computed tomographic features of active arterial hemorrhage. In our series, the pelvis was the most common source of active arterial bleeding, which was typically associated with unstable pelvic fractures.
authors.affiliation: Department of Medical Imaging, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ont. ryanmf@shb.ie
authors.forename: Max F
authors.initials: MF
authors.lastname: Ryan
authors.forename: Paul A
authors.initials: PA
authors.lastname: Hamilton
authors.forename: Peter
authors.initials: P
authors.lastname: Chu
authors.forename: John
authors.initials: J
authors.lastname: Hanaghan
mesh_terms: D000007:Abdominal Injuries / Q000000981:diagnostic imaging*; D000328:Adult; D000792:Angiography; D005119:Extravasation of Diagnostic and Therapeutic Materials; D005260:Female; D050723:Fractures, Bone / Q000000981:diagnostic imaging; D006470:Hemorrhage / Q000000981:diagnostic imaging*; D006801:Humans; D015601:Injury Severity Score; D016015:Logistic Models; D008297:Male; D010384:Pelvic Bones / Q000000981:diagnostic imaging / Q000293:injuries; D011860:Radiography, Abdominal; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014949:Wounds, Nonpenetrating / Q000000981:diagnostic imaging*