Detection of gastrointestinal hemorrhage

In patients with suspected gastrointestinal bleeding below the ligament of Treitz and above the limits of sigmoidoscope who can be clinically stabilized, Tc-99m erythrocytes offer a sensitive screening examination to identify the presence of active bleeding and frequently its site. The radionuclide gastrointestinal bleeding examination should be performed before angiography and, if the study is positive, angiography should be performed immediately to increase the chance of identifying the site of hemorrhage. Technetium-99m labeled erythrocytes by the in vitro technique has achieved a sensitivity of 91% and a specificity of 95% in detecting gastrointestinal bleeding. Thus, technetium-labeled erythrocytes is the radionuclide method of choice to evaluate gastrointestinal hemorrhage.