Efficient fat suppression in free-running whole-heart CMR using OptiPulse

The incomplete or time-inefficient suppression of fat signals is an unsolved issue in 3D cardiovascular MR imaging (CMR). We present a flexible framework named OptiPulse to design spectrally-selective radiofrequency (RF) pulses using numerical optimization of Bloch equation simulations. The RF pulse performance was assessed using a composite loss function for both fat suppression and power requirement. OptiPulse was used to design a B-splines-interpolated pulse for use in a free-running 3D whole-heart pulse sequence. Its fat suppression performance was ascertained both in vitro and in vivo, where it resulted in more homogeneous fat suppression when compared to other WE pulses (P<0.01).