Recently velocity-selective saturation (VSS) based dual-module (dm-) preparation and velocity-selective inversion (VSI) based preparation have demonstrated improved SNR efficiency in velocity-selective arterial spin labeling (VSASL) than conventional single-module VSS based preparation. In this study, a novel strategy was developed to allow dm-VSI labeling to further improve the SNR efficiency. Implementation of dm-VSASL were evaluated for VSS and/or VSI combinations. The theoretical performance was compared via ASL signal modeling, and then validated by in vivo human experiments with an increase of 6.6%. Dm-VSASL is capable of providing further improved SNR performance, with potentially better suppression of diffusion attenuation/eddy current artifacts.