Jiancheng Zhuang1, Zhong-Lin Lu1, Christine Bouteiller Vidal1, Hanna Damasio1
1University of Southern California, Los Angeles, CA, United States
High angular resolution diffusion images are susceptible to distortions caused by eddy currents induced by large diffusion gradients. A new post-acquisition correction algorithm is proposed which does not require any auxiliary reference scans. Image distortion parameters were obtained by image coregistration, performed only between diffusion weighted images with close diffusion gradient orientations. A linear model that describes distortion parameters (translation, scaling, and shear) as a function of diffusion gradient directions was numerically computed to allow individualized distortion correction for every diffusion-weighted image. The method avoids the problematic procedure of cross-correlating images with significantly different contrasts resulting from very different gradient orientations or strengths. Application of the proposed algorithm in high angular resolution diffusion images markedly reduced eddy current distortions, when compared to results obtained with previously published methods.