Bids Naming Convention for Changing Voltage scans

[Kevancic]

I am attempting to upload Changing Voltage Scans to Bids but there is no guidance on naming convention. For background changing voltage scans are direct files from the MRI scanner, they are 2mm scans used for our image corrections pipeline. An example of the name of these scans are below, FA is for Flip Angle and we collect about 16 of these during a scan, the number after the FA changes depending on the voltage scan. I have given some potential ideas of what the naming convention could be please advise if any of them are correct or if something else is needed.

Example of name on scanner: gre_1echo_2mm_PA_FA22p5_TR5s_lowSAR

potential naming convention:

Sub-X_ses-MRI_acq-FA112p5_ChangingVoltageScan.nii.gz Sub-X_ses-MRI_acq-FA135_ChangingVoltageScan.nii.gz

or

Sub-X_ses-MRI_flip-112p5_ChangingVoltageScan.nii.gz Sub-X_ses-MRI_flip-135_ChangingVoltageScan.nii.gz

[tsalo]

@Kevancic I'm not familiar with this type of scan. Could you provide links to papers or resources describing the scan in more detail?

EDIT: Googling "Changing Voltage Scan" doesn't return anything related to MRI, so I assume the terminology varies?

[tsalo]

Also, two things to note: (1) the sub entity should not be capitalized and (2) the flip entity takes an index, not a label, so flip- should have a number (e.g., flip-1, flip-2). The actual flip angle should then be included in the sidecar file with the FlipAngle field.

[Kevancic]

@tsalo I'll reach out to my team to ask which resources would be best to send because I'm not sure which would be the most helpful. As for your corrections noted above which sub entity are you referring to that should not be capitalized?

[tsalo]

I'll reach out to my team to ask which resources would be best to send because I'm not sure which would be the most helpful.

Thank you. Once we have a better handle on the scan we can pull in other folks, like the qMRI BEP leads, if necessary.

As for your corrections noted above which sub entity are you referring to that should not be capitalized?

I'm referring to sub-X, which you wrote as Sub-X.

[Kevancic]

Hi @tsalo I apologize for the delay in responding. Unfortunately I do not have any resources I can send you to read on changing voltage scans but from my understanding in discussing with my team they are a Flip angle map or a B1+ map. Please let me know if that helps a little more in understanding what they are.

[tsalo]

I'm not familiar with that type of scan, but the quantitative MRI appendix does document a few B1-mapping suffixes, such as TB1AFI. I'd recommend taking a look at those, and then, if the documentation isn't clear or your use case isn't covered, we could tag some of the qMRI contributors.

[sappelhoff]

@Kevancic I am closing this issue for now as it seems like more of a usage question. Please note that often https://neurostars.org/tag/bids is a better place for such usage questions. If this is still a problem for you, feel free to provide more information and we can re-open this.