Orientation convention in dcm and nifti

Hi everyone,
I am looking for the orientation convention in nifti and dicom.
It is well known that in axial, nifti uses the RAS orientation, while dicom uses LPS orientation.
But what about coronal and sagittal orientation?
I think that in dicom, it is LIP for coronal, and PIL for sagittal.
Could anyone validate this and share the results for nifti?
Best regards


This assumes identity orientation matrix.

This is the first time I hear that there could be a “standardized” orientation for sagittal and coronal scans.

Anyway, you should examine the orientation matrix and that will tell you what orientation it is in. See docs and implementation.

Since there is a convention for axial scans, I was wondering that there might be one for coronal and sagittal as well.
At least for dicom, it seems that there is such a convention since most of the cases I had to work with were oriented LIP/PIL for coronal/sagittal. Furthermore, it seems that some viewer use a convention because Mango/ITK SNAP/3D SLICER/RADIAN display the same cases with conflicting orientation: some are flipped left/right or up/down, others are 90° rotated,…
I’m trying to get the top of this and have something really consistent, so a convention would be useful here!
But I am happy if there is no convention, I can as well define mine for my use case :slight_smile:

This might be the consequence of working with data coming from the same institution, which uses the same manufacturer’s software and same settings.

I think you will need to do that. I recommend mirroring Slicer.