Abstract #3827

Image Reconstruction of Single-Shot North West EPI Data Acquired with PatLoc Gradients Using Magnetic Field Monitoring and Total Generalized Variation Conjugate Gradient

Stefan Kroboth¹, Frederik Testud², Kristian Bredies³, Kelvin J. Layton⁴, Daniel Gallichan⁵, Chris A. Cocosco², Gerrit Schultz², Florian Knoll¹, Christoph Barmet⁶,⁷, Klaas P. Pruessmann⁸, Maxim Zaitsev², Rudolf Stollberger¹

¹Institute of Medical Engineering, Graz University of Technology, Graz, Austria; ²Medical Physics, University Medical Center Freiburg, Freiburg, Germany; ³Institute for Mathematics and Scientific Computing, University of Graz, Graz, Austria; ⁴Department of Electrical and Electronic Engineering, University of Melbourne, Parkville, Victoria, Australia; ⁵LIFMET, Ecole Polytchnique Fdrale de Lausanne, Lausanne, Switzerland; ⁶Institute for Biomedical Engineering, University and ETH Zurich, Zrich, Switzerland; ⁷Skope Magnetic Resonance Technologies, Zrich, Switzerland; ⁸Institute for Biomedical Engineering, University of Zrich and ETH Zrich, Zrich, Switzerland

This work investigates the reconstruction of single shot North-West Echo Planar Imaging (NW-EPI) data with estimated trajectories using field cameras. NW-EPI is a multidimensional trajectory designed to improve the resolution in a selected region by exploiting the spatially varying resolution characteristic of nonlinear PatLoc fields. Reconstruction with Total Generalized Variation (TGV) was successfully applied to PatLoc imaging with 2D trajectories to reduce noise, Gibbs ringing and undersampling artifacts. However, for multidimensional trajectories, TGV converges very slowly. We therefore present a new concept of numerically solving the inverse problem, called Total Generalized Variation - Conjugate Gradient (TGV-CG) to increase convergence speed.