The purpose of this study is to assess the diagnostic accuracy in the detection and localization of acute gastrointestinal bleeding with contrast-enhanced helical CT

Between February 2003 and March 2004, twenty-one consecutive patients who presented with acute gastrointestinal bleeding were prospectively studied with 4-channel multidetector CT (MDCT) scans of the abdomen. On arterial phase MDCT scan, the diagnosis of acute hemorrhage was established when a focal high-attenuation area, indicating active contrast extravasation, was noted within the bowel lumen. The presence or absence of contrast extravasation, as well as the anatomic sites of contrast extravasation, was recorded. All patients underwent subsequent conventional angiography within 24 hours after CT examination. The results of CT were compared with those of angiography.

Conventional angiography revealed active bleeding sites in 19 patients: small bowel in 9, duodenum in 5, large bowel in 4, and stomach in one patient. Arterial phase images of contrast-enhanced MDCT scan revealed arterial extravasation in 17 of 19 patients. There were two false negative cases in the detection of duodenal bleeding. In the detection of acute gastrointestinal bleeding, contrast-enhanced MDCT had a sensitivity of 89.4% (17 of 19), specificity of 100% (2 of 2), and accuracy of 90.5% (19 of 21). The bleeding sites suspected on CT were exactly agreed with those noted on angiography in all 17 patients. All 19 patients with active bleeding site underwent transarterial embolization.

Contrast-enhanced MDCT is useful for the detection and localization of acute gastrointestinal bleeding. It can be used as guidance for subsequent angiographic intervention.