In
this simulation study we evaluate the TE that offers the optimum BOLD contrast
per unit time for a given field strength (taking into account the
field-specific T1, T2* and ΔT2* values) as a function of the number
of slice excitations to acquire the volume (minimum TR achievable), using the
Ernst angle for excitation. Generally, optimum BOLD sensitivity is found at TEs
closer to T2* when shorter TRs (higher multiband acceleration factors) are
employed. At longer TRs efficiency constraints tend to make the optimum TE
shorter with this effect being more pronounced at lower static fields.