BIDS folder structure for crossover design

1

Hello,
I’m trying to figure out how to organise the folders in a crossover design with 3 conditions that uses pre (1 run) and post (3 runs) assessments for brain perfusion images for every condition (ses-1, ses-2, ses-3).

The following is a proposal:

proposal
proposal604×1512 152 KB

I would appreciate any suggestions or feedback.

Best regards!

2

The easiest thing would probably be to use an acq entity to distinguish the pre and post scans from the same session. E.g.,

sub-01/
    ses-1/
        perf/
            sub-01_ses-1_acq-pre_run-1_asl.json
            sub-01_ses-1_acq-post_run-1_asl.json
            sub-01_ses-1_acq-post_run-2_asl.json
            sub-01_ses-1_acq-post_run-3_asl.json

Note that I had the run entity increment independently for the pre and post scans.

Alternatively, if the participants get out of the scanner between the pre and post scans, you could organize them as different sessions. E.g.,

sub-01/
    ses-visit1pre/
    ses-visit1post/
    ses-visit2pre/
    ses-visit2post/
    ses-visit3pre/
    ses-visit3post/

I think it would be misleading to do this if they don’t at least get out of the scanner though.

2 Likes