1. Pictorial Guide To The RCV Procedure
Red Cell Volume
Pictorial Guide To The RCV Procedure

2. Blood Volume Determination
The fundamentals of the dilution principle are
based on the following equation and hold true for all dilution type equations that are applied in vitro:
V = Q C
V = Volume Q = Dose of the activity injected
C = Sample of the activity extracted

3. Applications of formula
V = Q/C
Hence, by adding a known quantity of activity to an
unknown volume of liquid and extracted a sample from
the unknown liquid you can determine its volume.
This formula is the basis for all volume determinations
in nuclear medicine.

4. Equipment used Cr-51 Tag
Identify materials for the tagging of the RBCs
ACD vial
Shielding for ACD vial
Ascorbic Acid
Cr-51
Shielding
Cups for Standard Prep
Tubes for collecting RBCs

5. Preparing the syringe Wet a 20 cc syringe with 1 ml of ACD Solution.
Using a 19 gauge needle take the syringe and draw 15 ml of whole blood from the patient.

6. Preparing the blood for the tag
After drawing 15 ml of whole blood from the patient slowly add it to the ACD vial

7. Starting the tag
Add 100 uCi of Cr-51 to the ACD vial

8. Mixing the contents
Mix the contents in the ACD vial after adding contents
Mix every 5 to 10 minutes after that for a total of 30 minutes

9. Ampule of ascorbic acid
Concentration of ascorbic acid is 1000 mg/2ml
Calculate a 50 mg dose

10. Reducing the Cr-51 After 30 minutes add 30 - 50 mg of ascorbic acid
Mix contents again
This reduces the Cr-51 and locks it into the RBCs

11. End Product - Labeled RBCs
After waiting 5 minutes 10 ml is withdrawn from the ACD vial
Labeled RBCs are then injected into the patient
Dose circulates for 10 to 20 minutes before withdrawing WB2

12. Preparation of Standards
While the labeled RBCs are circulating in the patient make your standard.
99 ml of water is measured twice and added to two separate containers.

13. The Standards 1 ml of WB is added to 99 ml of H2O
After collecting a 4 ml blood sample it is spun down and 1 ml of Plasma is drawn off and added to 99 ml of H2O
2 - 4 ml samples from each container is drawn up to a test tube and labeled WB1 and Pl1

14. Patient’s Whole Blood
Using a 19 gauge needle with a 20 ml syringe approximately 20 ml of whole blood is drawn from patient
4 - 4ml purple top tubes are used to collect 4 equal samples of whole blood.
Three of these tubes are spin down to collect 4 ml of plasma for Pl2

15. What about the other tubes?
1 - 4 ml tube of patients whole blood is collected for WB2
1 - 4 ml blood sample is collected from ACD vial to determine Hct1 from ACD vial
1 - 4 ml blood sample is collected from pts to determine Hct2

16. Time to count Count bkg for 20 minutes Count all tubes for 20 minutes
Take them to the formula

17. Now just plug in the counts
WB1 - Pl1(1 - Hct1)
x Hct2 x 1000
= RCV in ml
WB2 - Pl2(1 - Hct2)

18. Return to the Table of Content