SIFT: visualizing the cost function gradient vector

Hi there,

I’m a bit new to DTI processing, but recently read your “SIFT: Spherical-deconvolution informed filtering of tractograms” paper and am wondering if there is a way to visualize the output of equation four in a volumetric file. Can we visualize the changes in the cost function over the course of sifting tracts? I think this would help me to compare two sequences that we are choosing between.

Thanks!
Mags M.

Hi Mags,

That’s an intriguingly unique question; I’m not sure I’ve ever even thought of looking at that specific data. There’s not any way currently to access those data; it would not require a great deal of coding effort to export it, though exporting it at every iteration would make your hard disk rather unhappy.

Having said that:

I think this would help me to compare two sequences that we are choosing between.

I don’t see how the data you’re looking for would assist in making that decision. Differences in the statistical distribution of that vector are in no way guaranteed to be correlated with the quality of the underlying DWI data. Indeed one would get drastic changes in that distribution by changing parameters of the tractography reconstruction, which is entirely independent of DWI data quality.

Cheers
Rob