Thanks Mark - really helpful What you describe is exactly what I am trying to do I have fieldmaps so have been using those with epi_reg to try and correct for some of the distortion Some are difficult still though Are there any DTI specific scripts/programs I can use on the DWI ADC map I have to improve the inferior frontal distortion? I have looked on the JISC pages and at the FDT/topup pages but cant see anything that might help Thanks Monty