Hi there.
We currently have multidimensional, multiframe enhanced dicom files containing diffusion tensor MRI scans on a preclinical Bruker scanner (X, Y, Z, B vector). The metadata containing B-vectors is handled with a Per-frame Functional Groups Sequence, which has quite a lot of frames (24 slices, 3 shells, 30 directions each).
When uploading these images to XNAT via the compressed folder (or the uncompressed dicom via REST), it seems that XNAT handles these per-frame functional groups by concatenating them together into a single dicom tag? As a result, it creates a long string that exceeds the DICOM 255 character limit (see error message below).
Extraction/Review failed: [bValues -> xs:string, Must Be Less Than 255 Characters : Current Length (1024), xnat:mrSessionData/imageSessionData/scans/scan[0]/parameters/diffusion/bValues, The content of element 'xnat:mrScanData' is not complete. '{"http://nrg.wustl.edu/xnat":parameters/diffusion/bValues}' Must Be Less Than 255 Characters : Current Length (1024)]
We would prefer to not just remove the b-values from the metadata, as it's critical for analysis. I'm assuming that there's no way to preserve the multiframe enhanced dicom structure in XNAT, so does anyone have any suggestions on the best way to handle this without just wiping out the B-value data before upload? If I were to modify the way in which the files were imported, where would this process occur? It doesn't seem to be explicitly stated in any of the import processor instances.
My backup plan is to create a b-matrix text file to upload alongside the DTI scans and just wipe the B matrix metadata from the dicom headers, but that's obviously not ideal.