Table 1.

The parameters, the signal-to-noise (SNR) efficiencies and the additional labeling efficiency terms (β) for the VS labeling schemes. These values were calculated based on Bloch simulation. The effective TE’s of dual-DRHS-VSS and dual-sBIR8-VSS were not listed because the two VSS modules have different effects on different sub-groups of the labeled bolus. The signal-to-noise ratio (SNR) efficiency of sBIR8-VSS was used as reference for calculation of the normalized SNR efficiency. Note that the standard deviation of the averaged SNR efficiency (and the normalized values) was calculated without Gaussian weighting. The additional labeling efficiency terms (β) were used in cerebral blood flow quantification to account for the additional labeling efficiency loss due to field imperfection.

	DRHS-VSS	dual-DRHS-VSS	sBIR8-VSS	dual-sBIR8-VSS	rect-VSI	segmented-sinc-VSI	mp-sinc-VSI	Sinc-VSI
Pulse Duration (ms)	23.8	23.8*2	24.4	24.4*2	49.4	67.6	69.1	69.1
Effective TE (ms)	20.6	--	20.7	--	26.8	28.8	27.8	31.3
Averaged SNR efficiency (a.u.)	0.118 ± 0.011	0.152 ± 0.014	0.126 ± 0.003	0.165 ± 0.004	0.149 ± 0.041	0.120 ± 0.058	0.169 ± 0.024	0.173 ± 0.025
Normalized SNR efficiency	0.935 ± 0.084	1.209 ± 0.110	1.000 ± 0.026	1.315 ± 0.035	1.181 ± 0.329	0.958 ± 0.465	1.3453 ± 0.192	1.378 ± 0.202
Additional labeling efficiency term (β)	0.922	0.922	0.983	0.983	0.727	0.609	0.880	0.881