Abstract #1047

Porter D

Non-linear 2D navigator-based phase correction is usually effective at removing artefacts in multi-shot diffusion-weighted imaging. However, it can fail sporadically due to high-spatial-frequency phase variation, for which the spatial resolution in the 2D navigator data is insufficient. This paper proposes a method for identifying data affected in this way based upon the measurement of the k-space signal distribution in a 2D navigator. It is also demonstrated how the information can be used during the measurement to reduce artefact by re-acquiring the unusable data. Sample data, acquired by combining the 2D-navigator-based re-acquisition scheme with the readout-segmented EPI sequence, are presented.