Ideally, conversion of a bedpostx output to BIDS compliance would only require basic image manipulation operations such as concatenation. I need to check the outputs of bedpostx on datasets with different orientations to see exactly how they encode those polar angles. If they don't conform to the ISO standard, then we will either need to define a third reference axis system over and above ['ijk', 'xyz'] to support those data directly, or unambiguously define the mathematical transformations required to get from bedpostx to BIDS and back again.
I have recently acquired a dataset that's ideal for this purpose: 24 combinations of slice encoding direction / slice order / phase encoding direction. So I can run bedpostx on all 24, then attempt conversion to scanner-space 3-vectors and check the result in mrview.
Ideally, conversion of a
bedpostxoutput to BIDS compliance would only require basic image manipulation operations such as concatenation. I need to check the outputs ofbedpostxon datasets with different orientations to see exactly how they encode those polar angles. If they don't conform to the ISO standard, then we will either need to define a third reference axis system over and above['ijk', 'xyz']to support those data directly, or unambiguously define the mathematical transformations required to get frombedpostxto BIDS and back again.I have recently acquired a dataset that's ideal for this purpose: 24 combinations of slice encoding direction / slice order / phase encoding direction. So I can run
bedpostxon all 24, then attempt conversion to scanner-space 3-vectors and check the result inmrview.