Vote: ADC and TRACE volumes

[Chris Markiewicz]

Hi all,

There's been an ongoing conversation about how to encode scanner-generated ADC and TRACE volumes from DWI sequences. The discussion petered out, but no decision was made, so I've opened an issue where people can vote: https://github.com/bids-standard/bids-specification/issues/1723

Here is the text of the issue for reference:

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Scanners are increasingly generating ADC/TRACE volumes, and BIDS now considers scanner-generated derivatives to be raw enough to not contort ourselves into moving portions of the output into a derivatives/ subdirectory.

These volumes right now are best considered DWI volumes, with no applicable bval/bvecs, but at least the validator expects DWI to be 4D and have bval/bvec sidecars.

I would like to push the issue and just have a vote. Here are our options (use the emoji responses to indicate your vote):

• 🎉 Carve out acq-ADC_dwi.nii[.gz] and acq-TRACE_dwi.nii[.gz] as special DWI images that can be 3D and not require bval/bvec.
• 🚀 Create TRACE and ADC suffixes that go in the dwi/ datatype directory to refer to single-volume images with no bval/bvec requirements.
• 👍 Either is fine, but please just fix this.
• 👎 Leave things as is.

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Please vote at the issue if you have any opinions at all, as more votes make more legitimacy. If you don't have a GitHub account and refuse to make one, feel free to respond here.

Best,

Chris