GASTROINTESTINAL BLEEDING STUDY

INDICATIONS:

Detection of active gastrointestinal and non-gastrointestinal bleeding sites Localization provides approximate location only. Although detection of gastric bleeding has been reported, this study is mainly limited to bleeding beyond the ligament of Treitz and is most sensitive for lower GI bleeding.

PATIENT PREPARATION:

None.

RADIOPHARMACEUTICAL:

20 mCi of Tc-99m-labeled to the patient's RBC's is used.

SCANNING TIME:

The blood must be labeled prior to scanning which requires about 30 minutes. Abdominal flow images are obtained immediately and sequential images are taken ever 5 minutes up to 60 minutes. The study may be terminated as soon as the site is identified. Delayed images may be required and performed up to 24 hours post injection.

OTHER CONSIDERATIONS:

1. Bleeding rates of 0.5 - 1 cc/minute can be detected.
2. The study does not provide exact localization.
3. Large (and in some cases - moderate) doses of heparin may cause poor labeling, yielding poor results. In such patients, arteriography may be the study of choice.

RATIONALE:

Radiolabeled RBC's serve as a marker to identify bleeding sites. Extravasation of RBC's into the bowel is diagnostic of a GI bleed; exact localization is not possible secondary to normal bowel transit of intraluminal contents.

NOTE: This scan may be ordered on an emergency basis.