Trong-Kha Truong1, Nan-Kuei Chen1,
Allen W. Song1
1Brain
Spiral imaging is a promising alternative to EPI for DTI because of its efficient k-space coverage and low sensitivity to flow artifacts. Multishot acquisitions are typically required to achieve a high resolution while minimizing off-resonance effects. However, shot-to-shot phase variations induced by motion in the presence of diffusion gradients lead to severe artifacts. Variable-density spiral trajectories can be used to correct for such artifacts, but result in a longer scan time. Here, we propose a novel iterative phase cycling method that can effectively and efficiently correct for motion-induced phase errors in multishot spiral imaging without requiring any additional navigator.
Keywords