Abdominal blood pool scintigraphy in the management of acute or intermittent gastrointestinal bleeding.

Gastrointestinal blood pool scintigraphy, using a modified in-vivo red blood cell labelling technique with technetium-99, is a new, easily performed, non-invasive procedure. It is valuable in screening patients with acute or intermittent gastrointestinal blood loss in whom duodenoscopic and sigmoidoscopic findings are unhelpful. This paper reviews the value of this scintigraphic technique over the first eight months of its use in a major teaching hospital, and compares the results with other published data. The high sensitivity of this procedure, and its ability to demonstrate gastrointestinal bleeding very strikingly, are illustrated with several examples. If used and interpreted appropriately, scintigraphy is sensitive in detecting and localizing the bleeding site, and is very helpful in indicating the optimal timing of emergency contrast angiography. The study further supports the view that scintigraphy should be the initial diagnostic imaging procedure in this group of patients, and that emergency angiography should be reserved primarily for patients in whom there is scintigraphic evidence of continuing blood loss.