Improved Image Reconstruction for Multi-Shot Multi-Coil Diffusion Imaging

Martin Uecker¹, Alexander Karaus¹, Jens Frahm¹

In multi-shot diffusion imaging each segment is affected differently by phase variations caused by brain pulsation during the diffusion gradients. For this reason image reconstruction requires phase maps for each segment. Since the resolution of the maps obtained with navigator based approaches is limited by its size, images reconstructed from strongly disturbed data suffer from residual phase cancellation. Reconstructing each segment independently with parallel imaging allows to calculate phase maps with high resolution avoiding phase cancellation problems during the reconstruction. The proposed technique was applied to data from a segmented STEAM sequence where large 2D-navigators are not feasible.