Fig. 5.

Percent mean error or bias (A,C) and scatter in the error or SD (B,D) in the estimated value of the reaction rate constant k for simulated ³¹P FAST experiments of the CK reaction as a function of the SNR levels for the PCr signal in the 15° γ-ATP-saturation experiment, as determined by a 100-run Monte Carlo simulation. The value of k over both the wide range (0.05 ⩽ k ⩽ 1.0; (A,B); k_{Eq. (11)} using FAST coefficients from Table 4), and the more restrictive physiological range (0.1 ⩽ k ⩽ 0.5; (C,D); k_{Eq. (11)} using FAST* coefficients), was sampled by 6 points, as were T_1A, ω₁, and M_0A/M_0B over the ranges listed in Table 2. For each run, the mean error in k was calculated for the 6⁴ combinations of variables in the range, and the mean and SD error for the 100 runs reported.