Variation in Gated Blood-pool Image Quality Using In Vivo, Modified In Vivo, and In Vitro Red Blood Cell Labeling Techniques

The scintigraphic results of three methods of labeling red blood cells (RBCs) were compared. Image quality was evaluated in 200 patient studies by measuring the left ventricle to background ratio. These studies were performed using either the in vivo, modified in vivo or in vitro method for labeling RBCs. The average ventricle to background ratio for the in vitro method was 2.85 compared to 2.42 and 2.20 for the modified in vivo and in vivo methods, respectively. The in vitro method gave a statistically higher ratio than did either the in vivo or the modified in vivo methods.