Hi again,
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>> if you take a look at https://fsl.fmrib.ox.ac.uk/fsl/fslwiki/eddy/Faq you should be able to figure out what your acqparams.txt and your index.txt should look like.
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> There's a lot of information about this file. I understand. Because exists a lot of possibilities for all those parameters. But on my case, I really not using different phase encodings. Images are acquired with 1.5 Tesla GE Scanner. I will send informations obtained when DICOM to Nifiti conversion are made, could you help me to find how these informations are correlated with I need to put in --acqp file:
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>
> Phase encoding direction : COL
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The line above tells you that phase-encoding is in the A<->P direction, though it doesn’t say if it is A->P or P->A. There is no information about the dwell time or readout time. But that doesn’t matter for your case. Just use
0 1 0 0.05
as your acqparams.txt file.
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> on this case with 35 volumes (first 3 volumes are b0's but with bvectors [0 0 0] (same encoding directions) and bvals 0) and just one phase encoding direction for all, I will need a --index file with 35 number 1's?, like:
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> 1 1 1 1 1 1 1 1 1 .... (35 times)?
yes.
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>> I am afraid I don’t see anything there that looks like a fieldmap. In order to get a fieldmap you need to explicitly run a fieldmap sequence as part of your experiment.
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> Could create this artificially?
No, if the information hasn’t been acquired there is no way of creating it.
Jesper
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>> I see. The first dtifit is run _only_ to make sure that the bvecs are in the correct format for FSL. You only use it to visualise the V1 file in fslview and ensure that the lines line up between voxels. Once you have done that you can throw away the output from the first run of dtifit and proceed as if you had never run it.
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> Nice! Its like more a Quality control step. Cool.
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> Thank you very much
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> Best Wishes
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> David
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>> Jesper
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