Increasing the Effectiveness of the UNFOLD Technique by Removing Phase Trends

Yanle Hu¹

To increase temporal resolution in dynamic MRI studies, under-sampling techniques are typically used. One way to remove aliasing artifacts associated with under-sampling is to use the UNFOLD technique, which purposely interleaves under-sampled k-space trajectories across time frames to move aliasing peaks away from true signal peaks in the spectrum, and then filter out aliasing peaks to get alias-free images. The phase drift in signal may shift and broaden aliasing peaks. Removing linear and quadratic phase trends before the implementation of UNFOLD can ensure that aliasing artifacts are removed effectively without increasing the number of frequency components to be filtered out.