Abnormal pelvic venous collaterals demonstrated during a gastrointestinal bleeding study

A Tc-99m blood cell study, performed on a patient with suspected gastrointestinal bleeding, demonstrated an unusual configuration of pelvic venous collaterals associated with idiopathic iliac vein occlusion. The cause of these findings subsequently was confirmed by intravenous digital subtraction angiography. This case demonstrates the importance of the dynamic phase of gastrointestinal bleeding studies in correctly identifying vascular abnormalities.