Gastro bleeds give it up to multiphasic, multidetector CT

The source and cause of gastrointestinal bleeding can be notoriously difficult to pinpoint, but French researchers have found 64-slice multiphasic, multidetector CT up to the job. Diagnostic and Interventional Imaging published the team’s findings online June 25.

Eimad Shotar, MD, of Lariboisière Hospital in Paris and colleagues compared the diagnostic accuracy of the modality at finding, specifically, acute overt gastrointestinal bleeding across three image-acquisition phases—arterial, portal venous and combination.

They examined 49 patients (30 men and 19 women, age range 34 to 91 years). Two observers reviewed, by consensus, multidetector CT exams for the presence of active bleeding, location of the bleeding site and the nature of the lesion causing the bleed.

The researchers identified acute overt gastrointestinal bleeding in 28 patients (57 percent) with the multiphasic set, in 26 patients (53 percent) with the arterial phase and in 25 patients (51 percent) with the portal venous phase.

The multiphasic set helped locate the bleeding site in 40 patients (82 percent), they report.

The cause was clear in 23 patients (47 percent) in the multiphasic set, which had satisfactory specificity, 76 percent, to go along with its high sensitivity, 92 percent.

The differences between set performances were not statistically significant, the authors note, adding that they consider all phases important in depicting active bleeding and elucidating the cause of the bleeding.

Multiphasic 64-section multidetector CT “has high diagnostic performance in patients with middle and lower acute overt gastrointestinal bleeding,” they conclude.

“Our results suggest that 64-section multidetector CT should be used as a first line diagnostic option in middle and lower acute overt gastrointestinal bleeding and as an alternative diagnostic procedure in case of negative upper endoscopy in upper acute overt gastrointestinal bleeding,” Shotar et al. write.

The authors call for further studies to investigate radiation dose in the procedure and to test its diagnostic performance when using low-dose protocols.