False Positive GI Bleed on Tc-99m RBC Scintigraphy Due to Ileal Varices

Abstract

Tc-99m labeled RBC scintigraphy is commonly employed in the evaluation of acute gastrointestinal bleeding. On Tc-99m RBC studies gastrointestinal bleeding is seen as an initial focus of increased radiotracer activity that on subsequent images increases in intensity and changes position in a pattern that conforms to segments of bowel. We report a case of a patient with multiple episodes of hematochezia that presented with lower gastrointestinal hemorrhage. A Tc-99m labeled RBC scan was performed and the findings suggested a GI bleed. However, subsequent angiography revealed prominent ileal varices simulating an acute bleed. Although most varices fill promptly and should not be misinterpreted as a focus of hemorrhage, slow filling varices can simulate an acute bleed and lead to a false positive interpretation.