The99mTc-labeled RBC scan

Abstract

The experience with 62 99mTc-labeled in vivo scans performed for lower gastrointestinal bleeding is discussed. Scans (37) were deemed positive. The tendency of scans to become positive correlated with observations of active bleeding. Patients (5) had fulminant hemorrhage, necessitating emergency operation. In this group, scanning accurately located the bleeding sources prior to intervention. Seven other patients having later operations bled less rapidly. The bleeding site was localized accurately by scanning in 3 of these patients. Two studies were falsely positive and 2 were negative, whereas angiography was positive in 2 patients studied. Labeled RBC [red blood cell] scanning is a useful technique in the early evaluation of patients with lower gastrointestinal bleeding, obviating the need of arteriography in some cases.