Figure 1

CNR normalized by the minimum CNR value. CNR normalized by the minimum CNR value (8) according to the activity concentration in all spheres for TOF reconstruction (A), non-TOF reconstruction (B), the 13-mm diameter (C), and the 17-mm diameter sphere (D). The thick line ( in panels A and B) is the minimum normalized CNR value (1) above which the detectability could be considered as true. Experimental data points were fitted to highlight the relationship between CNR and activity concentration.