PT  - JOURNAL ARTICLE
AU  - Rousseau, A.J.
AU  - Royal, H.D.
AU  - Parker, J.A.
AU  - Kolodny, G.M.
TI  - Technical Considerations of Tc-99m Labeled Red Blood Cell Scans in the Detection and Localization of Gastrointestinal Bleeding Sites
DP  - 1984 Jun 01
TA  - Journal of Nuclear Medicine Technology
PG  - 56--58
VI  - 12
IP  - 2
4099  - http://tech.snmjournals.org/content/12/2/56.short
4100  - http://tech.snmjournals.org/content/12/2/56.full
SO  - J. Nucl. Med. Technol.1984 Jun 01; 12
AB  - Arteriography to detect gastrointestinal bleeding, which is often intermittent, is only likely to yield diagnostically useful information if the patient is actively bleeding at a rate of greater than 1.0 cc/min at the time of the procedure. To avoid the unnecessary morbidity of a negative arteriogram we studied Tc-99m in vitro labeled red blood cell (RBC) scintigraphy as a screening test for arteriography on 111 patients. Fifty-seven of 111 patients (51%) had RBC scans consistent with active gastrointestinal bleeding. Twenty-three of these patients (40%) with positive scans had arteriography. Twelve of these 23 arteriograms (52%) were positive. Arteriograms were performed in 12 of the 54 patients with a negative scan. One of the 12 arteriograms was positive for active bleeding in the rectum. In retrospect, the scan was also positive but rectal activity was initially confused with bladder activity. Red blood cell scans are a reliable screening test for arteriography and they provide useful localizing information in patients with negative arteriograms. Technical factors that will affect the results include (1) obtaining high labeling efficiency by using in vitro labeled red blood cells; (2) frequent acquisition of images over a 24-hr time period; (3) acquisition of dynamic images to localize confusing patterns of activity; and (4) acquisition of images to separate rectal and bladder activity.