Accelerating Data Acquisition for Reversed-Gradient Distortion Correction in Diffusion MRI: A Constrained Reconstruction Approach

Chitresh Bhushan¹, Anand A. Joshi², Richard M. Leahy², Justin P. Haldar²

EPI-based diffusion MRI suffers from localized distortion artifacts in the presence of B0 inhomogeneity, which can cause problems in multi-modal image analysis and when estimating quantitative diffusion parameters. These distortions can be partially corrected with measured field maps, though performance improves substantially if each image is acquired twice with reversed phase encoding gradients (at the expense of doubling the scan time). In this work, we propose a novel acquisition and reconstruction strategy that leverages a constrained reconstruction formulation to enable accurate distortion correction with similar performance to the reversed gradient method, but without increasing the scan time.