Dynamic Correction of Artifacts Due to Susceptibility Effects & Time-Varying Eddy Currents in DTI

Trong-Kha Truong¹, Nan-Kuei Chen¹, Allen W. Song¹

DTI is vulnerable to variations of the static magnetic field caused by susceptibility effects as well as eddy currents induced by the diffusion gradients. Their dependence on space, time, and/or diffusion direction causes distortions, blurring, and misregistration, leading to errors in the derivation of the diffusion tensor. Existing correction methods assume that the eddy currents remain constant within the readout window or decay monoexponentially, which is known not to be the case. Here, we propose a novel dynamic correction method that measures their exact time dependence and can effectively and efficiently correct for both susceptibility- and eddy current-induced artifacts.