2. GI BLEEDING SCAN
• A GI bleeding scan is an imaging test that can help to detect the
origin of the gastrointestinal bleeding.
• During the test, blood will be drawn from your vein.
• The drawn blood will be mixed with a radiopharmaceutical
called Technetium-99m.
• The blood cells will then be reinjected into the vein.
• A special gamma camera is used to take pictures of the abdomen
once the blood cells have been reinjected.
3. CLINICAL SIGNIFICANCE:-
• Gastrointestinal bleeding is a noninvasive procedure and it is
helpful to determine approximate location and severity of the
bleeding with detection rates as low as 0.1 mL/m.
• The radiation exposure with GIBS is lower than a three-phase
CT Angiography.
4. How is the Test Performed?
• Method 1:-
• The RBCs are tagged with radioisotope in 1 of 2 ways.
• The first method involves removing blood from a vein.
• The red blood cells are separated from the rest of the blood sample.
The cells are then mixed with the radioactive material. The cells with
the radioactive material are considered "tagged." A short time later
the tagged RBCs are injected into one of your veins.
5. • Method 2:-
• The second method involves an injection of medicine. The
medicine allows the radioactive material to attach to your red
blood cells. The radioactive material is injected into a vein 15 or
20 minutes after you receive this medicine.
6. INDICATIONS:-
• GIBS should not be used for chronic occult bleeds.
• To identify the source of the obscure overt bleed
• Risk identification in GI bleeding
• Directing timely diagnostic angiography
• It can detect GIB at a rate as low as 0.1mL
7. LIMITATIONS:-
•The limitations of Tc scintigraphy include limited
availability and a delay of several hours before the
examination is initiated.
•Poor anatomic localization of the bleeding identified at RBC
scintigraphy may result in misdiagnoses (eg, colon vs small-bowel
bleeding right vs left colonic bleeding) and subsequent errors at
therapeutic interventions
9. Reference
• Bentley, D. E., & Richardson, J. D. (1991). The role of tagged red blood cell
imaging in the localization of gastrointestinal bleeding. Archives of Surgery
(Chicago, Ill.: 1960), 126(7), 821–824.
https://doi.org/10.1001/archsurg.1991.01410310031003
• Cable, C. A., Razavi, S. A., Roback, J. D., & Murphy, D. J. (2019). RBC Transfusion
Strategies in the ICU: A Concise Review. Critical Care Medicine, 47(11), 1637–
1644. https://doi.org/10.1097/CCM.0000000000003985
• Pavel, D. G., Zimmer, M., & Patterson, V. N. (1977). In vivo labeling of red blood
cells with 99mTc: A new approach to blood pool visualization. Journal of Nuclear
Medicine: Official Publication, Society of Nuclear Medicine, 18(3), 305–308.
