1. Red Cell Sequestration
Non Imaging In Vivo
Red Cell Sequestration

2. Red Cell Sequestration
Done in conjunction with red cell survival
Used to determine if destruction of RBC’s, which causes shortened RBC survival, is due to splenic destruction of RBC’s

3. Procedure for RC Sequestration
Tag blood same as for Red Cell Survival
After 24 hour sample is drawn for Red Cell Survival, place patient under a thyroid probe and obtain counts over:
Anterior liver
Right lateral liver
Anterior heart (blood pool)
Left lateral spleen
Posterior spleen

4. Procedure Continued
Positioning probe is done by finding the area of the most counts over each organ.
Once this place is located, the technologist needs to mark that location with a permanent marker.
This ensures the same spot will be counted each time.
This procedure will be repeated on the same days that blood is drawn for a Red Cell Survival Study
Obtain a ratio of Liver/Spleen

5. Findings
Normal ratio is 1.0 or greater, but should be as close to 1 to 1 as possible
This value should remain approximately the same ratio over the course of the study.
Abnormal findings would be an increased spleen to liver ratio or the value steadily increases throughout the study.
Splenomegally itself, without pathologic sequestration can yield spleen to liver ratios of 2:1 or 4:1.
For this reason, rising ratios are the best evidence of significant sequestration
Liver disease will show a short survival time, but an increase in splenic counts

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