Significance of intensity of delayed activity during technetium-99m-RBC gastrointestinal bleeding study

In 27 patients with normal hepatic function, delayed concentration of radioactivity (during 99mTc-RBC gastrointestinal bleeding studies) was compared with liver blood-pool activity. That is, for images at 4 to 24 hr postinjection, grading was accomplished by comparison to the liver blood pool (less than, equal to, or greater than hepatic activity). There was a correlation between the accuracy of scan interpretation (for active bleeding and localization) and the intensity of activity as related to the liver. This simple grading system may be useful for interpretation of delayed images during bleeding studies.