Motion Correction for Diffusion-Weighted Segmented EPI: Performance of an Iterative Parameter Space Searching Technique Evaluated with Numerically Simulated Motion Artifacts
Winter J, Gelman N, Thompson R
Lawson Health Research Institute, University of Western Ontario
The performance of a motion correction technique was assessed by simulating motion artifacts that occur in diffusion-weighted segmented EPI. The simulations involved perturbing the inter-segment phase differences of an artifact free image. The motion correction method evaluated, employs an iterative parameter space search to determine the 0th and 1st order phase corrections for each segment. For images with simulated artifacts having artifact to signal ratios (ASR) of less than 20%, the corrected images displayed very low artifact levels (ASR < 1%). The algorithm accurately determined phase correction values provided that the 1st order phase perturbations were less than certain limits.