Abdominal wall hematomata and colonic tumor detected on labeled red blood cell scintigraphy: case report

Omental Hernia as a Potential Cause of False-Positive GI Bleeding on 99mTc-RBC Scintigraphy

ABSTRACT

Gastrointestinal bleeding scintigraphy is a noninvasive study used to determine the presence of active bleeding, localize the bleeding site, and estimate the bleeding volume for prognostic purposes in patients with suspected gastrointestinal bleeding. However, it is important to note that false-positive results can occur due to various reasons. In this case, we present the scenario of a middle-aged woman who exhibited symptoms of gastrointestinal bleeding and underwent 99mTc-RBC scintigraphy. The imaging revealed an accumulation of radiotracer in the hypogastric region, which was later determined to be caused by an omental hernia on SPECT/CT images. The herniated structure caused congestion in the mesenteric vessels, leading to the accumulation of 99mTc-RBC. This case highlights the significance of considering anatomical anomalies and nonbleeding pathologies when interpreting the 99mTc-RBC scintigraphy results for gastrointestinal bleeding.

Intravenous blood pool activity masquerading as gastrointestinal hemorrhage

Radiolabeled red blood cell (RBC) scintigraphy is a common study to detect and localize gastrointestinal hemorrhage. There are many potential entities that may result in false-positive RBC scintigraphy. Here, we present a case of enlarged feeding vessels of omental carcinomatosis which scintigraphically might be mistaken as intraluminal bowel activity and thus active hemorrhage. This case highlights the importance of reviewing correlative imaging in patients with a large neoplastic burden.

False positive GI bleed on Tc-99m RBC scintigraphy due to ileal varices

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.