Appendix IV: Entity table

This section compiles the entities (key-value pairs) described throughout this specification, and establishes a common order within a filename.  For example, if a file has an acquisition and reconstruction label, the acquisition entity must precede the reconstruction entity. REQUIRED and OPTIONAL entities for a given file type are denoted. Entity formats indicate whether the value is alphanumeric (<label>) or numeric (<index>).

A general introduction to entities is given in the section on file name structure, while entity definitions are in Appendix IX.

Magnetic Resonance Imaging

Entity	Subject	Session	Task	Acquisition	Contrast Enhancing Agent	Reconstruction	Phase-Encoding Direction	Run	Corresponding Modality	Echo	Recording
Format	sub-<label>	ses-<label>	task-<label>	acq-<label>	ce-<label>	rec-<label>	dir-<label>	run-<index>	mod-<label>	echo-<index>	recording-<label>
anat (T1w T2w T1rho T1map T2map T2star FLAIR FLASH PD PDmap PDT2 inplaneT1 inplaneT2 angio)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL
anat (defacemask)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL	OPTIONAL
dwi (dwi sbref)	REQUIRED	OPTIONAL		OPTIONAL			OPTIONAL	OPTIONAL
fmap (phasediff phase1 phase2 magnitude1 magnitude2 magnitude fieldmap)	REQUIRED	OPTIONAL		OPTIONAL				OPTIONAL
fmap (epi)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL		REQUIRED	OPTIONAL
func (bold cbv phase sbref events)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL
func (physio stim)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL		OPTIONAL		OPTIONAL			OPTIONAL

Encephalography (EEG, iEEG, and MEG)

Entity	Subject	Session	Task	Acquisition	Run	Processed (on device)	Space	Split
Format	sub-<label>	ses-<label>	task-<label>	acq-<label>	run-<index>	proc-<label>	space-<label>	split-<index>
eeg (eeg)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL
ieeg (ieeg)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL
meg (meg)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL
meg (headshape)	REQUIRED	OPTIONAL		OPTIONAL			OPTIONAL
meg (markers)	REQUIRED	OPTIONAL	OPTIONAL	OPTIONAL			OPTIONAL
channels (meg eeg ieeg)	REQUIRED	OPTIONAL	REQUIRED		OPTIONAL
electrodes (eeg ieeg)	REQUIRED	OPTIONAL		OPTIONAL			OPTIONAL
events (meg eeg ieeg)	REQUIRED	OPTIONAL	REQUIRED		OPTIONAL
photo (meg eeg ieeg)	REQUIRED	OPTIONAL		OPTIONAL

Behavioral Data

Entity	Subject	Session	Task	Acquisition	Run	Recording
Format	sub-<label>	ses-<label>	task-<label>	acq-<label>	run-<index>	recording-<label>
beh (stim physio)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL	OPTIONAL
beh (events beh)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL