Acute gastrointestinal hemorrhage detected by selective scintigraphic angiography.

Intra-arterial 99mTc colloid scintigraphy may have greater sensitivity than either standard intravenous scintigraphy or selective arteriography in detecting gastrointestinal bleeding. Ten millicuries of 99mTc colloid were administered directly into the superior and inferior mesenteric arteries (SMA and IMA) of patients who had undergone selective arterial catheterization for the evaluation of gastrointestinal bleeding. In one patient, 99mTc-albumin colloid was administered directly into the IMA and identified diverticular bleeding. The bleeding had been occult to prior contrast arteriography and refractory to selective intra-arterial Pitressin therapy. In a second patient who had undergone three negative provocative angiograms, selective SMA injection of 99mTc-sulfur colloid identified occult mesenteric varices secondary to portal hypertension. Selective intra-arterial scintigraphy should be valuable in detecting intestinal bleeding occult to conventional studies. This will help in directing further therapy and diagnostic evaluation.