There's nothing in SPM, but there are approaches out there:
Poynton, Clare, Mark Jenkinson, and William Wells Iii. "Atlas-Based
Improved Prediction of Magnetic Field Inhomogeneity for Distortion
Correction of EPI Data." In Medical Image Computing and
Computer-Assisted Intervention–MICCAI 2009, pp. 951-959. Springer
Berlin Heidelberg, 2009.
Studholme, Colin, R. Todd Constable, and James S. Duncan. "Accurate
alignment of functional EPI data to anatomical MRI using a
physics-based distortion model." Medical Imaging, IEEE Transactions on
19, no. 11 (2000): 1115-1127.
Publications are generally considered to be the research output of
modellers, so I'm not sure if there is any free software available.
Best regards,
-John
On 23 May 2013 07:13, Andrew Martin <[log in to unmask]> wrote:
> Hello
> Are there any methods for correcting distortion without gradient field maps?
> Thanks
> Andrew
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