Dear all,

I'm trying to use grad_unwarp to correct for the gradient nonlinearities. Construction of the .coef and .gwv files from the .grad file provided by Siemens seems to work fine. Infact, "grad_warp -i in.mhz -o out.mgz -u sonata" also runs without any problem.

However, the image obtained looks like a field map of the gradients not the corrected image.

Did I miss some important step?

Thanks in advance,

Martijn