Hi
I have coronal brain diffusion data acquired with both LR and RL encoding (1 b=0 and 43 b=1200 in each direction, total of 88 images) and would like to use all the data to correct the image distortion.
I have used topup to estimate and correct susceptibility induced distortions using the b0s:
topup --imain=LR_b0 --datain=acqparams.txt --config=b02b0.cnf --out=TU_LR_b0 --iout=hifi_LR_b0
And I am trying to use eddy:
eddy --imain=LRmerge --mask=hifi_LR_b0_brain_mask --acqp=acqparams.txt --index=index.txt --bvecs=bvecs --bvals=bvals --topup=TU_LR_b0 --resamp=lsr --out=ec_LR_merge
This works with --resamp=jac, but with --resamp=lsr I get an error message:
eddy: msg=These data do not support least-squares resampling
I have repeated the bvecs and bvals to account for the 88 images and I have tried indexing with 1111....2222 and 1111...23333.....4 to define where the b0 is.
Has anyone any tips as to what else I could try or where other people have gone wrong? I see that there are a few others on the list who have had similar problems but can't see any resolution.
Thanks,
Penny
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