Table 1.

Parameter values used for the simulations. References are given for parameters taken from the literature.

δa (arterial transit time)	500 ms (24)
δ (tissue transit time)	1500 ms (23)
τ (labeling duration)	1500 ms (Typical value in our laboratory)
w (post-inversion delay)	700 ms (21)
CBF (baseline)	60 ml/(100g min) (20)
CBF (increase over baseline)	50% (20)
BOLD signal (increase over baseline)	2% at TE = 35 ms (Typical value in our laboratory) Corresponds to ΔR2* = 0.566 s−1
λ (blood-brain partition coefficient)	0.9 ml blood/g brain
α (labeling efficiency)	0.8 (Typical value in our laboratory)
T1a (T1 of arterial blood)	1660 ms (22)
T1app (apparent T1 in gray matter)	1300 ms (43)
T2* of gray matter at 3 Tesla	40 ms (43)
# slices	30
TE	Double-Excitation: 11 ms for ASL, 35 ms for BOLD Double-Echo: 11 ms for ASL, 35 ms for BOLD Single-Excitation Single-Echo: 15 ms, 20 ms, 25 ms, 30 ms
Time to Acquire Each Slice	TE + 7 ms
TR	Double-Excitation: 3958 ms Double-Echo: 3418 ms Single-Excitation Single-Echo: 2838 ms, 2983 ms 3128 ms, 3273 ms
SNR0 (Image SNR at TE = 30 ms)	866 (19)
λ (physiological noise constant at TE = 30–35 ms)	0.0092 (19, 25)
λ (physiological noise constant at TE = 25 ms)	0.0083 (25)
λ (physiological noise constant at TE = 20 ms)	0.0075 (25)
λ (physiological noise constant at TE = 15 ms)	0.0067 (25)
λ (physiological noise constant at TE = 10–11	0.0059 (25)