Independent usefulness of flow phase 99mTc-red blood cell scintigraphy in predicting the results of angiography in acute gastrointestinal bleeding.

Negative flow phase scintigraphy identifies patients who will not benefit from invasive catheter angiography despite positive results on subsequent dynamic phase scintigraphy. Increasing the delay between positive red blood cell scintigraphy and catheter angiography progressively reduces the likelihood of identifying extravasation, which is required to target embolization.