search

bids-standard / bep001

Project management repository (primarily issues) for BIDS Extension Proposal 001
Creative Commons Attribution 4.0 International
8 stars 11 forks source link

Include B1map in anatomical data listing #40

Closed Gilles86 closed 5 years ago

Gilles86 commented 5 years ago

We use B1 maps for improving the T1 estimation of MP2RAGEs. Noted that they were not included yet in current draft.

agahkarakuzu commented 5 years ago

Data acquired to correct for B0 inhomogeneities can come in different forms.`

This is how field maps is currently described in the mainspec. It accounts for 4 different scenarios, all focusing on B0 maps. Plus there are some fixed suffixes such as magnitudeN, phaseN and fieldmap.

Should we suggest changes there to make the whole spec more compliant, or just leave it as is?

Gilles86 commented 5 years ago

I'm not sure. That part of the spec was clearly written from the fMRI use-case and only one out of 4 scenarios talks about a proper, quantitative B0map. I think we should not touch hat part of the spec. To be honest, I would even argue again to put he B1map "just" in the anat-folder, to keep things simple. What do you think?

agahkarakuzu commented 5 years ago

@Gilles86 now that I better see your point.

As long as we clearly explain the reasons why these maps are not going into the fmap folder, putting B1map in the anat folder looks like a good idea. Can we add B0map in this case ass well?

tiborauer commented 5 years ago

Is B1map a separate acquisition, or part of the MP2RAGE? If it is a separate one (just like the fieldmaps for fMRI), then I cannot see why it should not go to fmap

Gilles86 commented 5 years ago

It is a different acquisition altogether, with, as I understood, many possible approaches and sequences actually.

KirstieJane commented 5 years ago

Heya! Thanks for having this discussion @Gilles86 @tiborauer & @agahkarakuzu.

I think we should update the fieldmap section (https://bids-specification.readthedocs.io/en/stable/04-modality-specific-files/01-magnetic-resonance-imaging-data.html#fieldmap-data). Why not just add a fifth example?

agahkarakuzu commented 5 years ago

@KirstieJane should we just add descriptions only for B1Map itself or also for descriptions for source files that may be used to create them (e.g. Double angle mapping using segmented EPI)?

The fieldmap section is already a mixture of both (I guess, I am a bit lost in that section).

Gilles86 commented 5 years ago

The fieldmap section is already a mixture of both (I guess, I am a bit lost in that section).

Also, it explicitly only deals with B0 maps:

Data acquired to correct for B0 inhomogeneities can come in different forms. The current version of this standard considers four different scenarios.

I guess we could add a fifth category wit suffix _b1map.

Gilles86 commented 5 years ago

Let's close this and let it be superseded by pull request #48