I’ve generally viewed the
_run- label as an optional field except for
func acquisitions. I realize that the BIDS specification contains this important line regarding runs
If several scans of the same modality are acquired they MUST be indexed with the
_run-3, and so on (only nonnegative integers are allowed as run labels).
which leads me to a couple case-scenario questions:
1). If I were to collect two separate
anat/T1w acquisitions, but the parameters were different and noted in the
_ce-, or some other label, would the run label still be necessary for these two?
2). If I collect four
dwi/dwi acquisitions (two AP, two PA), do the run numbers need to go 01-04, or is this appropriate:
sub_01_dir-AP_run-01_dwi.nii.gz sub_01_dir-PA_run-01_dwi.nii.gz sub_01_dir-AP_run-02_dwi.nii.gz sub_01_dir-PA_run-02_dwi.nii.gz
My impression is that BIDS doesn’t particularly care, but I’m curious if there’s some preferred method?