The technetium-99m-sulfur colloid angiogram in suspected gastrointestinal bleeding.

Dynamic radionuclide angiography (5-sec. images) with technetium-99m-sulfur colloid proved to be helpful in 5 patients who presented with gastrointestinal bleeding. In 2, intermittently bleeding hypervascular lesions were seen on dynamic but not on static images; in 2 others, the dynamic images demonstrated hypervascular lesions better than the static scans; and in 1, the radionuclide angiogram localized colonic bleeding more accurately because of rapid peristalsis of extravasated tracer. The addition of the radionuclide angiogram to routine scintigraphy for gastrointestinal bleeding may be crucial for identification of hypervascular lesions and precise localization of bleeding sites.