Journal of Nuclear Medicine Technology, Vol 25, Issue 1 44-48, Copyright © 1997 by Society of Nuclear Medicine
Ultratag RBC kit for combined cardiac first-pass and multigated acquisition studies
LE Stallings, KT Cheng, KM Spicer, R Wiegner and JK Humphries
Department of Nuclear Medicine, Medical University of South Carolina, Charleston 29425, USA.
The authors developed a procedure to use the in vitro Ultratag
(Mallinckrodt, St. Louis, MO) red blood cell (RBC) labeling kit for both
first-pass (FP) and multigated acquisition (MUGA) studies with a high
specific activity in a reduced volume (50 mCi/0.5 ml) and a high labeling
efficiency that can be used with a single-crystal camera to yield a quality
study. METHODS: A packed red blood cell (PRBC) bolus was created by two
methods: (a) reducing the volume of the components of the Ultratag kit and
(b) centrifuging the final dose volume. The labeling efficiency of each
bolus was evaluated, each PRBC bolus was visually inspected for clots and
percent hemolysis was assessed using a hemocytometer at 30 min, 1 hr and 2
hr postcentrifugation. RESULTS: Use of the first method, the 50% kit,
provided the best results. However, the resulting volume from this kit only
approached 1 ml, which is not clinically adequate for a first-pass study.
In the second method, the total volume was centrifuged to form a PRBC
bolus, which appeared to be stable in the syringe for at least 2 hr. A
combined FP/MUGA study from a centrifuged 50% reduced kit was performed in
one normal subject as a preliminary assessment of the clinical utility of
this procedure. The image quality of the scan is diagnostically adequate.
CONCLUSION: By using the in vitro Ultratag kit, a compact PRBC bolus was
created that was stable in the syringe and could be reinjected safely into
the patient for combined cardiac FP/MUGA studies.
