That's correct. Though if the subject has moved THAT much the data is
probably unusable for a variety of practical reasons.
Cheers.
On 16 Aug 2007, at 02:12, Ruth wrote:
> Hi,
> I was just rereading the thread on averaging multiple DTI
> acquisitions. As
> I understand it, the suggestion was to rotate the 2nd acquisition
> to line up
> with the first acquisition, then continue with tensor calculation.
> Am I
> correct that this would only be valid with small rotations? For
> example, if
> one of the acquisitions had to be rotated 30 degrees in order to
> line up
> with the other (because the subject had moved their head within the
> scanner), the directions recorded in it's original bvecs file
> would no
> longer be accurate. That being the case, the 2 acquisitions, with
> different
> bvecs, couldn't be directly averaged. Is this correct?
>
> --Ruth
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Stephen M. Smith, Professor of Biomedical Engineering
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