Journal of Nuclear Medicine Technology, Vol 27, Issue 3 222-226, Copyright © 1999 by Society of Nuclear Medicine
High RBC labeling efficiency by controlling pretinning with the modified in vivo/in vitro labeling method
R Kuehne and E Reuter
Department of Radiology and Nuclear Medicine, Wenckebach Hospital, Academic Teaching Hospital of the Free University of Berlin, Germany.
OBJECTIVE: The image quality for gastrointestinal bleeding studies depends
on the efficiency of red blood cell labeling. The in vitro technique has
been used widely because of its high labeling efficiency. New data for the
modified in vivo/in vitro method are lacking. This study reports on the
high labeling efficiency that can be obtained with the modified in vivo/in
vitro method and the pitfalls to avoid. METHODS: A consecutive series of 91
labeling studies was analyzed. Different amounts of tin, red blood cell
concentrations, and infusions of interfering substances also were studied.
RESULTS: A mean efficiency of red blood cell labeling of 97% (80%-99%) was
obtained. Only 3 cases showed unacceptable results. Suboptimal results were
obtained with amounts of tin below 10 microg SnCl2/kg body weight, a
reduced hematocrit, and blood transfusion or infusion of HES solution
during pretinning. CONCLUSION: The modified in vivo/in vitro red blood cell
labeling technique is performed easily, is useful and is comparable to the
gold standard in vitro method, provided that the pretinning period is
controlled carefully.
