Flow-suppressed 2D Spin-Echo EPI with high B1-insensitivity using Hyperbolic Secant Pulses

Blood flow artifacts sometimes occur in 2D spin-echo sequence despite its intrinsic flow-suppression effect. Pre-saturation pulses have widely been used for flow-suppression, but it has several disadvantages such as requirement of additional RF pulses and being not effective at suppressing relatively slow blood flow signal. In this study, we propose a more effective flow-suppressed spin-echo sequence using hyperbolic-secant (HS) pulses for π/2-excitation and π-refocusing. The proposed method was applied to 2D spin-echo diffusion EPI for liver imaging.