Allow "B" and "U" as valid values for "hemi-<label>"

[andersonwinkler]

Dear all,

We currently have hemi-L and hemi-R for left and right hemispheres respectively.

I'd like to propose that we also allow for:

• hemi-B for files that contain structures for both hemispheres (B standing for both or bilateral)
• hemi-U for files that contain structures that are unique or not lateralized (U standing for unique).

For example, suppose I have a mask for the left amygdala and one for the right amygdala. If they are in separate files, I can currently name them with hemi-L and hemi-R. But suppose I merge both masks into one file and want to retain the convenience of keeping file names consistent with the lateralized versions to simplify scripts. Then the file with both amygdalae would use hemi-B.

Another example: I merge surface data for left and right cortices to run a joint statistical analysis, or render them together in some application and save that scene for later reuse. That merged file for stats or the scene file for viewing would use hemi-B.

For structures that are unique or which we don't in general artificially split by a sagittal plane, e.g., brain stem, pons, periaqueductal gray, corpus callosum, pineal, hypophysis, fornix, optic chiasm, basilar artery, all the great sinuses, 3rd and 4th ventricles, and various other structures, we would use hemi-U, where U would stand for "unique".

What do you think?

Thanks!

Anderson

[effigies]

B makes sense. It's not clear that U is necessary, but a controlled vocabulary of 4 items instead of 3 makes little difference.

+1 from me.