[Mristudio-users] Coordinate system for diffusion-gradient directions?

[Nanz Daniel Dr.]

Hi

I could not find definitions for the coordinate
system within which the diffusion directions are to
be defined for the input into DTI studio?

E.g., on a Philips system, the diffusion direction
cosines found in the DICOM header (private and public tags)
are independent of slice orientation as well as of
patient orientation. Presumably, the direction cosines
are given in a magnet-fixed coordinate system.

Is this considered and recalculated for tractograpy
by DTI studio, based on the information in the DICOM
header (slice orientation in patient coordinate system)?
Or is the inter-voxel relation of diffusion
ellipsoid directions neglected altogether by DTI studio?

Or should the directions be re-calculated before
feeding the data into DTI studio? If so, into what
coordinate system should the directions be transformed?

With best regards and thanks
Dani Nanz