[Mrtrix-discussion] Encoding.b value questions

[JSP]

Dear MRTRIX experts,

First of all, I just got introduced to the world of DTI and MRTRIX as well.

I'm having some issues with my data, especially the encoding.b file
generated after I performed the "mrinfo -grad" command-line.  Here is the
situation.  First of all I'm working with the NIFTI format, so I have
converted my data using the the "mrconvert" command.
My paramaters used here is b=1000, direction=20, average=4.  When I look at
the encoding.b file resulting from the "mrinfo -grad", we noticed that the
values are repeting themselves every 20 lines in the first three columns for
4 times instead of being all different.  Is that supposed to be that way ?

I executed the "estimate_response" function but the values are way out of
this world: 5.62455e+77 -9.96597e+75 3.52424e+76 -4.63953e+76 -3.93348e+75
7.96634e+76.  A colleague of mine noticed that the lmax was equal to 10 when
I performed the "disp_profile" rendering suggesting that maybe mrtrix was
considering that my data had 80 directions instead of 20.  Is that good
reasoning ?
How can I go around this problem ?

Thank you very much for your help,

JS  

    

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