Abstract
The reproducibility of area/length ejection fraction determinations was evaluated in 21 subjects using (99m)Tc labeled red blood cells ((99m)Tc RBCs). The ejection fraction was determined within 30 min and 3 to 5 hr after a single injection of (99m)Tc RBCs. The mean absolute difference between the initial and subsequent ejection fractions was 7% (maximum, 15%) (r=0.90). (99m)Tc RBCs offer a reproducible method of determining the ejection fraction which is suitable for serial noninvasive evaluations of left ventricular function.