Removing Background Velocity Errors in PC-MRI with Optimized Spoiler Gradient Waveforms

Motivation: Background velocity errors caused by eddy currents and mechanical oscillations in PC-MRI are a significant source of measurement error for which prospective corrections remain unavailable. Goal(s): To prospectively design spoiler gradient waveforms that reduce background velocity errors to levels generally considered irrelevant. Approach: A gradient optimization toolbox (GrOpt) was used in conjunction with a gradient impulse response to design error-minimizing waveforms. They were tested in a phantom and in 10 volunteers. Results: Background velocity errors were reduced by 84±10.4% with the gradient spoiler optimization and to levels below a clinically relevant threshold (0.4% Venc) in 96% of subjects. Impact: We used a gradient optimization (GrOpt) toolbox and the gradient impulse response function to prospectively design spoiler gradient waveforms that reduce background velocity errors in PC-MRI to levels below a clinically relevant threshold in 96% of subjects.