BIDS naming for Fat/Water reconstruction with Dixon sequence


How should one be naming BIDS data with the fat and water reconstruction from the Dixon method applied to a fast low angle shot 3D sequence?

I’d think something like this maybe?

  • sub-XX_acq-fl3d_rec-water.nii.gz
  • sub-XX_acq-fl3d_rec-fat.nii.gz

Which brings me to my second question: are there any standardized values for the field -rec listed somewhere? I found this link but it is unclear to me what could be the possible values (or is it at the full discretion of the user, and if so, would we want to bring some standard values here?).


Hi Julien,

I don’t know anything about the sequence or reconstruction you’re asking about (sorry!), so hopefully someone who does will follow up here. However, purely from a BIDS filename construction perspective, you’re going to need a suffix to have a valid name.

The only thing I can see here is that it’s a FLASH sequence, but the FLASH suffix is deprecated since it doesn’t convey any contrast information. Do any of the suffixes listed in the MRI entity table fit?

AFAIK, rec accepts a freeform alphanumeric label. Certainly, some labels might be more common if certain tools use them, such as rec-magnitude and rec-phase, which were used by heudiconv before we added the part entity to BIDS, but I don’t believe there are any standardized labels for it.

Sorry I can’t help much.


Thank you @tsalo ! This is very helpful.

In this case we’ll probably throw the T1w label.

Looking at the list of possible values, I am a bit confused: what is the difference between T2starw and T2star (I assume that T2star is not the relaxation parameter, which corresponds to T2starmap). Same comment for PDw vs. PD.

Also, I still see the value FLASH in this table, but as you said I though it was deprecated?


T2star is deprecated, since it could mean either T2starw (T2*-weighted) or T2starmap (quantitative T2* map). (Same for PD.)

Also, I still see the value FLASH in this table, but as you said I though it was deprecated?

Deprecated suffixes

thanks @effigies, may i suggest to not list in the table the values that are deprecated? someone finding this table without knowing what values are deprecated might use them