Hi,
The lines of the eigenvectors were not right- in the meaning that what should have been left-right (and red) was anterior-posterior (and green).
So, at first I started to change the vectors to negative with many different combinations.
But yesterday I was told to change the values themselves (so the value of x to y and y to x) and after processing, I have now lines with right directions (so, corpus callosum fibers are from left to right, not from anterior to posterior).
So, now with the right directions, I can do the tractography.
Thanks,
Christine
>>> [log in to unmask] 12/01/04 1:16 PM >>>
Can you give me a little more detail. What is wrong with your
eigenvectors?
Or, is there anyway you can take a screen grab of the problem, and put it
on the web somewhere?
Thanks
Tim
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Tim Behrens
Centre for Functional MRI of the Brain
The John Radcliffe Hospital
Headley Way Oxford OX3 9DU
Oxford University
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On Wed, 1 Dec 2004, Christine Ojango wrote:
> Hi,
>
> the higher -level analysis worked now. Thank you.
>
> But I have another question about fdt.
>
> I have processed data from Philips scanner. And running the eddy current, dtifit and bedpost have been without errors. Bedpost datacheck is not giving me errors.
>
> The bvals are:
> 0 1000 1000 1000 1000 1000 1000
>
> And the bvecs:
> 0 0 1 0 0.70710678 0 0.70710678
> 0 1 0 0 0.70710678 0.70710678 0
> 0 0 0 1 0 0.70710678 0.70710678
>
>
> But the lines (and colours) watching with fsl view are not right. I have been told that it can be the difference of how the vectors are acquired and I ran all the possible changes in vector directions.
> Putting negative in front of x or x/y or x/z etc. And also turning the slices order from descending to ascending.
>
> But in all cases the lines of main eigenvector are not right.
>
> Is there somehing else what could I do?
>
> Thank you for the help.
>
> Christine
>
>
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