Image Reconstruction Using the Gradient Impulse Response for Trajectory Prediction

Nadine N. Graedel¹, Signe Johanna Vannesjo¹, Lars Kasper¹, Simon Gross¹, Benjamin E. Dietrich, Christoph Barmet¹, ², Klaas P. Pruessmann¹

Assuming that the gradient chain behaves as a linear time-invariant system, a gradient impulse response function (GIRF) can be determined. A measured GIRF was used in this work to predict the actual k-space trajectories for EPI image reconstructions. This allowed for reduction of ghosting caused by encoding field imperfections. Some residual artifacts remain as compared to using trajectories obtained with concurrent field monitoring. The GIRF method however does provide a simple tool for artifact reduction for arbitrary k-trajectories, and depending only on a one-time calibration of the system.