Value of contrast-enhanced CT in detecting active hemorrhage in patients with blunt abdominal or pelvic trauma.

OBJECTIVE: The purpose of this retrospective study was to evaluate the use of contrast-enhanced CT to show sites of active hemorrhage as a guide for surgical or angiographic treatment in patients sustaining blunt abdominal or pelvic trauma.

MATERIALS AND METHODS: Twenty-six CT scans were reviewed to compare the location or locations of extravasated contrast material (representing hemorrhage) detected on CT scans with the site or sites of active hemorrhage determined by surgery (eight patients), angiography (14 patients), or autopsy (one patient). (The three remaining patients had no additional studies done.) The attenuation of extravasated contrast material on CT scans was measured and compared with the CT attenuation of an adjacent artery. The attenuation of clotted blood within the abdomen or pelvis was also measured in 20 other patients with blunt trauma.

RESULTS: The locations of active bleeding as determined by extravasation of contrast material shown on CT scans included the pelvis (nine), spleen (five), retroperitoneum (four), kidney (three), liver (three), adrenal glands (one), and abdominal wall (one). Two patients had venous extravasation. The origin of bleeding was confirmed in all cases to correspond to the anatomic region in which extravasated contrast material was shown by CT. Three patients had only CT evidence of vascular extravasation of contrast material. The CT attenuation of active hemorrhage ranged from 85 to 370 H (mean, 132 H). A review of 20 additional CT scans that showed clotted blood in the abdomen or pelvis resulting from blunt abdominal trauma revealed a CT attenuation range of 40-70 H (mean, 51 H). These values were significantly different (p < .001) from the values for active hemorrhage.

CONCLUSION: Active extravasation of contrast material (representing bleeding) can be detected in trauma patients who are physiologically stable enough to undergo CT of the abdomen or pelvis. Extravasated contrast material can be distinguished from clotted blood by measuring CT attenuation. CT accurately shows the anatomic location of bleeding and indicates the probable vascular origin. CT, therefore, can be used as a guide for angiographic or surgical intervention.