Hello,

I am currently trying to use ARTS with my dataset, and I noticed that the script expects the DTI Phase Encoding Direction to be specified simply as either vertical or horizontal.

This terminology is confusing from an MR neuroimaging perspective, since phase encoding is usually defined either in image space (ROW/COL, i/j axes) or in anatomical space (AP/PA, LR/RL, SI/IS), rather than vertical/horizontal. 

In my dataset, the metadata shows for example "PhaseEncodingAxis": "j" and "InPlanePhaseEncodingDirectionDICOM": "COL". By conventions, this corresponds to the column direction (j axis), which in image space is the column axis, but depending on viewer orientation and world-coordinate mapping, this may appear visually vertical or horizontal.

So how can I set phase encoding safely as vertical or horizontal?

Thank you very much for your time.

Cheers,

Raniery