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; empty cells imply that entities MUST NOT be specified. Entity formats indicate whether the value is alphanumeric (<label>) or numeric (<index>).

A general introduction to entities is given in the section on filename 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	Flip Angle	Inversion Time	Magnetization Transfer	Part	Recording
Format	sub-<label>	ses-<label>	task-<label>	acq-<label>	ce-<label>	rec-<label>	dir-<label>	run-<index>	mod-<label>	echo-<index>	flip-<index>	inv-<index>	mt-<label>	part-<label>	recording-<label>
anat (T1w T2w PDw T2starw FLAIR inplaneT1 inplaneT2 PDT2 angio T2star FLASH PD)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL						OPTIONAL
anat (T1map T2map T2starmap R1map R2map R2starmap PDmap MTRmap MTsat UNIT1 T1rho MWFmap MTVmap PDT2map Chimap S0map M0map)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL
anat (defacemask)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL	OPTIONAL
anat (MESE MEGRE)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL		REQUIRED				OPTIONAL
anat (VFA)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL		OPTIONAL	REQUIRED			OPTIONAL
anat (IRT1)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL				REQUIRED		OPTIONAL
anat (MP2RAGE)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL		OPTIONAL	OPTIONAL	REQUIRED		OPTIONAL
anat (MPM MTS)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL		OPTIONAL	REQUIRED		REQUIRED	OPTIONAL
anat (MTR)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL					REQUIRED	OPTIONAL
dwi (dwi sbref)	REQUIRED	OPTIONAL		OPTIONAL			OPTIONAL	OPTIONAL						OPTIONAL
dwi (physio stim)	REQUIRED	OPTIONAL		OPTIONAL			OPTIONAL	OPTIONAL						OPTIONAL	OPTIONAL
fmap (phasediff phase1 phase2 magnitude1 magnitude2 magnitude fieldmap)	REQUIRED	OPTIONAL		OPTIONAL				OPTIONAL
fmap (epi m0scan)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL		REQUIRED	OPTIONAL
fmap (TB1DAM)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL			REQUIRED	OPTIONAL		OPTIONAL
fmap (TB1EPI)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL		REQUIRED	REQUIRED	OPTIONAL		OPTIONAL
fmap (TB1AFI TB1TFL TB1RFM RB1COR)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL
fmap (TB1SRGE)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL		OPTIONAL	REQUIRED	REQUIRED		OPTIONAL
fmap (TB1map RB1map)	REQUIRED	OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL
func (bold cbv sbref)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL				OPTIONAL
func (phase)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL		OPTIONAL
func (events)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL
func (physio stim)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL							OPTIONAL
perf (asl aslcontext m0scan)	REQUIRED	OPTIONAL		OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL
perf (asllabeling)	REQUIRED	OPTIONAL		OPTIONAL		OPTIONAL		OPTIONAL
perf (physio stim)	REQUIRED	OPTIONAL		OPTIONAL		OPTIONAL	OPTIONAL	OPTIONAL							OPTIONAL

Biopotential Amplification (EEG and iEEG)

Entity	Subject	Session	Task	Acquisition	Run	Space	Recording
Format	sub-<label>	ses-<label>	task-<label>	acq-<label>	run-<index>	space-<label>	recording-<label>
eeg (coordsystem electrodes)	REQUIRED	OPTIONAL		OPTIONAL		OPTIONAL
eeg (channels eeg events)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL
eeg (photo)	REQUIRED	OPTIONAL		OPTIONAL
eeg (physio stim)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL		OPTIONAL
ieeg (coordsystem electrodes)	REQUIRED	OPTIONAL		OPTIONAL		OPTIONAL
ieeg (channels events ieeg)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL
ieeg (photo)	REQUIRED	OPTIONAL		OPTIONAL
ieeg (physio stim)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL		OPTIONAL

Magnetoencephalography (MEG)

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

Positron Emission Tomography (PET)

Entity	Subject	Session	Task	Tracer	Reconstruction	Run	Recording
Format	sub-<label>	ses-<label>	task-<label>	trc-<label>	rec-<label>	run-<index>	recording-<label>
pet (pet)	REQUIRED	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL
pet (blood)	REQUIRED	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL	REQUIRED
pet (events)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL	OPTIONAL
pet (physio stim)	REQUIRED	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL	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

Microscopy

Entity	Subject	Session	Sample	Acquisition	Stain	Run	Chunk
Format	sub-<label>	ses-<label>	sample-<label>	acq-<label>	stain-<label>	run-<index>	chunk-<index>
micr (TEM SEM uCT BF DF PC DIC FLUO CONF PLI CARS 2PE MPE SR NLO OCT SPIM)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL	OPTIONAL	OPTIONAL	OPTIONAL
micr (photo)	REQUIRED	OPTIONAL	REQUIRED	OPTIONAL