Systems and methods for fast reconstruction for quantitative susceptibility mapping using magnetic resonance imaging

摘要

Described here are systems and methods for quantitative susceptibility mapping (“QSM”) using magnetic resonance imaging (“MRI”). Susceptibility maps are reconstructed from phase images using an automatic regularization technique based in part on variable splitting. Two different regularization parameters are used, one, λ, that controls the smoothness of the final susceptibility map and one, μ, that controls the convergence speed of the reconstruction. For instance, the regularization parameters can be determined using an L-curve heuristic to find the parameters that yield the maximum curvature on the L-curve. The μ parameter can be determined based on an l2-regularization and the λ parameter can be determined based on the iterative l1-regularization used to reconstruct the susceptibility map.

主权项

1. A method for performing quantitative susceptibility mapping using a magnetic resonance imaging (MRI) system, the steps of the method comprising:
a) acquiring data from a subject using the MRI system; b) reconstructing phase images from the acquired data; c) computing at least one initial estimate of a susceptibility map based on the reconstructed phase images; d) determining a first regularization parameter based on the at least one initial estimate of the susceptibility map; and e) reconstructing a susceptibility map using an l1-minimization that comprises iteratively minimizing an objective function that includes the first regularization parameter and a second regularization parameter, wherein the second regularization parameter is undated in each iteration based on iterative updates to the susceptibility map in that iteration.