Hi,
I used flirt to undo some of the damage induced by eddy currents which occur
during diffusion weighted imaging. What I did was a slice by slice 2D affine
match.
In order to keep the resolution as high as possible, I used the sinc
interpolation during the final reslice step. However, I noticed that the
resliced images contained negative values, whereas the input only contained
positive values. When I changed the interpolation step to trilinear, these
negative values did not occur.
Unfortunately, during FA and ADC reconstruction, negative values are
undefined. Therefore I cannot use the sinc-resliced images.
We discussed the occurence of negative values, and concluded that it should
not be possible if the input only contains positive values. So we think there
might be a bug in the sinc interpolation module. Does anyone agree?
Thanks,
Erik-Jan Vlieger
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