Hello IIT forum,

thanks to the developers for providing this great atlas. When trying to use it with DTI-TK and the JHU atlas I've encountered the following challenge:

I want to use tensor based registration techniques by DTI-TK and register subject images to the IIT Atlas. Then I want to perform tractography on the IIT Atlas with the provided FOD data. Afterwards I would like to extract fiber bundles through JHU ROIs.

My understanding at the moment is as follows:

- DTI-TK requires the 256 voxel version of IIT. In this version, the origin is set to 0 and the orientation is LPI.
- The JHU atlas is, like the IITAtlas, in ICBM152 space. The transform of the non 256 voxel versions of the IITAtlas is:

1 0 0 -91
-0 1 0 -126
-0 0 1 -72

Therefore, I want to linearly transform the JHU atlas by this transformation (and probably also flip the x-axis ?) in order to be in the DTI-TK compatible space. Unfortunately neither just a linear transform (or the inverse) or a transform and a flip on the x axis has yielded good results.

What am I doing wrong?

Thanks for your help,
Darius