Abstract #0115

In Vivo Correction of Non-Linear Phase Patterns for Diffusion-Weighted FSE Imaging Using Tailored RF Excitation Pulses

Rita G. Nunes¹,², Shaihan J. Malik³, Joseph V. Hajnal³

¹Institute of Biophysics and Biomedical Engineering, Faculty of Sciences, University of Lisbon, Lisbon, Portugal; ²Robert Steiner MRI Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Hammersmith Hospital, Imperial College London, London, United Kingdom; ³Robert Steiner MRI Unit, Imaging Sciences Department, MRC Clinical Sciences Centre,, Hammersmith Hospital, Imperial College London, London, United Kingdom

Unlike Echo-planar imaging, single-shot fast spin-echo is insensitive to field inhomogeneities but it requires precise control of the phase of the magnetization prior to the start of the refocusing train (CPMG condition). Due to motion, this is very difficult to achieve when diffusion-weighting is applied in vivo. Previously it has been shown that linear phase errors can be measured and corrected for in real time using gradients. The remaining non-linear phase modulations can be prospectively corrected using tailored RF excitation pulses as demonstrated on phantoms. Here the method is further developed and shown to be effective for in vivo imaging.