Echo-planar imaging-based time-of-flight imaging using a modified interleaved flyback trajectory

1.1 Purpose A modified interleaved flyback (miFB) approach is introduced, designed to mitigate flow artifacts caused by alternating readout polarities in Echo Planar Imaging (EPI), while preserving acquisition efficiency. 1.2 Methods We propose reconstructing odd and even echoes of 3D-EPI separately. To this end, the respective missing lines are acquired in interleaved shots with inverted polarity and an additional precursor gradient. Thereby, high scan efficiency is maintained compared to unsampled flyback gradients. Our miFB approach is additionally combined with gradient moment smoothing and compared to the interleaved dual-echo with acceleration (IDEA) method in phantom and in vivo scans at 7 Tesla. 1.3 Results Our results demonstrate a significant reduction in ghosting and signal dropout using the miFB approach, yielding comparable image quality to non-EPI acquisitions while reducing acquisition time by approximately half. 1.4 Conclusion The miFB approach offers a substantial reduction in flow artifacts, allowing for decreased acquisition times in TOF-MRA. Key words: Echo planar imaging, 3D-EPI, Flow artifacts, 7 T, Magnetic resonance angiography