BIDS mixed sessions

Hi all,

The dataset I’m working with has participants with a mixed number of sessions. Some have one session, others, more than one.

When organizing into BIDS, is it in keeping with the structure for all participants have the data in a sess directory?

So for participants with single sessions the structure is:
subj1 > sess-01 > data

and for multiple sessions:
subj2 > sess-01 > data
subj2 > sess-02 > data


Looks fine to me.
You could run a validator, though, in any case.

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Yes, keeping your data within a session directory is BIDS compliant.

Note: In case your example was your proposed bids structure; it should be sub-1 not subj1, and ses-1 not sess-01.


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Just a follow up, differing sessions between participants is fine for BIDS. The validator gives a warning, but not an error.

Just remember to put ses-01 in the data filename (eg. sub-subid_ses-01_T1w.nii.gz)…

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