Fig. 3

a Total measured activity within the FOV compared to the true activity, averaged across the eight sites. The dashed line represents the identity (i.e., where measured equals true). b Error in measured activity within the FOV. Each point represents the mean measured activity across the eight sites. Error bars represent one standard deviation across the eight sites’ measurements. The shaded region represents ± 10% error. c Mean activity concentration of the 37 mm VOI within the warm background compartment of the phantom compared to the true activity concentration, averaged across the eight sites. The dashed line represents the identity (i.e., where measured equals true). d Deviation of measured activity concentration within warm background. Each point represents the mean measured activity concentration of the 37 mm VOI across the eight sites. Error bars represent one standard deviation across the eight sites’ measurements. The shaded region represents ± 10% error