  Wave-CAIPI MR imaging is a 3D imaging technique which can uniformize the
g-factor maps and significantly reduce g-factor penalty at high acceleration
factors. But it is time-consuming to calculate the average g-factor penalty for
optimizing the parameters of Wave-CAIPI. In this paper, we propose a novel fast
calculation method to calculate the average g-factor in Wave-CAIPI imaging.
Wherein, the g-factor value in the arbitrary (e.g. the central) position is
separately calculated and then approximated to the average g-factor using
Taylor linear approximation. The verification experiments have demonstrated
that the average g-factors of Wave-CAIPI imaging which are calculated by the
proposed method is consistent with the previous time-consuming theoretical
calculation method and the conventional pseudo multiple replica method.
Comparison experiments show that the proposed method is averagely about 1000
times faster than the previous theoretical calculation method and about 1700
times faster than the conventional pseudo multiple replica method.
