Method to reduce eddy current effects in diffusion-weighted echo planar imaging

摘要

In an MR system disposed to generate an EPI pulse sequence to acquire MR images, wherein said pulse sequence includes a specified gradient and requires a number of EPI spatial encoding gradients, an eddy current correction method comprising the steps of: deriving eddy current parameters respectively associated with eddy current magnetic fields caused by said specified gradient; generating a set of correction terms comprising first and second correction term subsets, each of said correction terms being a function of said parameters; selectively modifying a set of ideal EPI gradients in accordance with said correction terms, each of said ideal EPI gradients comrising a first gradient component occurring prior to acquisition of said data, and a second gradient component occurring during acquisition of said data, the first and second gradient components of a given one of said ideal gradients being modified by correction terms of said first and second subsets, respectively; and employing said modified EPI gradients as the said required EPI gradients for said pulse sequence to substantially reduce artifacts of said acquired MR data resulting from said eddy current fields.