Iain T. Pierce1, 2, Peter D. Gatehouse1, 2, David N. Firmin1, 2
1NHLI, Imperial College London, London, United Kingdom; 2CMR Unit, Royal Brompton Hospital, London, United Kingdom
Spiral readouts are used due to their efficient coverage of k-space, but longer durations increase sensitivity to off-resonance. For spiral through-plane flow imaging, two sources of phase curvature over the vessel cross-section, velocity encoding and frequency off-resonance, can interact in a complex manner and cause in-vivo contraction and dilation artefacts of the vessel, distorting the velocity distribution and the peak velocity measurement.