Improved B0-Distortion Correction in Diffusion MRI Using Interlaced q-Space Sampling and Constrained Reconstruction

PurposeTo enable high-quality correction of susceptibility-induced geometric distortion artifacts in diffusion magnetic resonance imaging (MRI) images without increasing scan time. Theory and MethodsA new method for distortion correction is proposed based on subsampling a generalized version of the state-of-the-art reversed-gradient distortion correction method. Rather than acquire each q-space sample multiple times with different distortions (as in the conventional reversed-gradient method), we sample each q-space point once with an interlaced sampling scheme that measures different distortions at different q-space locations. Distortion correction is achieved using a novel constrained reconstruction formulation that leverages the smoothness of diffusion data in q-space. ResultsThe effectiveness of the proposed method is demonstrated with simulated and in vivo diffusion MRI data. The proposed method is substantially faster than the reversed-gradient method, and can also provide smaller intensity errors in the corrected images and smaller errors in derived quantitative diffusion parameters. ConclusionThe proposed method enables state-of-the-art distortion correction performance without increasing data acquisition time. Magn Reson Med 72:1218-1232, 2014. (c) 2013 Wiley Periodicals, Inc.