Fig. 4.

Lines of best fit (y = 100 − ae^(−bx)) for recovered concentrations in hot spheres of various diameters on day-0 imaging for (a) GE Healthcare ToF systems (R ² = 0.94 – 0.98), (b) GE Healthcare non-ToF systems (R ² = 0.90 – 0.99), (c) Philips ToF systems (R ² = 0.97 – 0.98), (d) Philips non-ToF systems (R ² = 0.90 – 0.96), (e) Siemens ToF systems (R ² = 0.80 – 0.99), (f) Siemens non-ToF systems (R ² = 0.94 – 0.97) (where +RAN and -RAN correspond to data acquired in ‘PROMTS + RANDOMS’ and ‘NETTRUES’ mode, respectively, and where -RAN was normalized for analysis). The black line of reference is the recovery curve for ¹⁸F derived from the same experiment