Localization of obscure gastrointestinal bleeding by technetium 99m-labeled red blood cell scintigraphy

J Formos Med Assoc. 1992 Jan;91(1):63-8.

Abstract

When a bleeding source from the gastrointestinal (GI) tract cannot be identified with conventional diagnostic studies, it is known as GI bleeding of an obscure origin. In the past three years, in vivo Technetium 99m-labeled red blood cell scintigraphy (RBC scan) has been added to our armamentarium for the diagnosis of obscure GI bleeding. Out of a total of 26 cases, the bleeders could be detected in 12 or 46.2% by RBC scan. The time required ranged from 15 minutes to 24 hours (median, one hour). In 14 patients with active bleeding during the scan period, 11 had positive scans (sensitivity, 78.6%). In 12 patients with inactive bleeding, 11 had negative scans (specificity, 91.7%). Angiography was conducted in nine cases, with all showing negative findings; however, six of them had a positive focus by RBC scan. Laparotomy was performed in seven scan-positive patients, and in three scan-negative patients because of a positive Meckel's scan (two cases) or recurrent bleeding (one case). Of the 12 scan-positive patients, incorrect localization was noted in two patients due to rapid transit of the labeled RBC in the small bowel. False localization could be prevented by shortening the sequential imaging interval. It is concluded that an RBC scan is a very sensitive and safe tool for detection of GI bleeding of an intermittent nature, because the bleeder can be monitored for 24 hours after a single injection. It can be used as a preangiographic screening test and to guide the surgeon in surgical planning or decision-making.(ABSTRACT TRUNCATED AT 250 WORDS)

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Angiography
  • Child
  • Child, Preschool
  • Erythrocytes / diagnostic imaging*
  • Female
  • Gastrointestinal Hemorrhage / diagnostic imaging*
  • Humans
  • Male
  • Middle Aged
  • Radionuclide Imaging
  • Technetium*

Substances

  • Technetium