Separate JSON file - params.json
Series collection parameters are stored in a separate JSON file called params.json stored in the series directory. The JSON object is an array of key-value pairs. This can be used for MRI sequence parameters.
All DICOM tags are acceptable parameters. See this list for available DICOM tags https://exiftool.org/TagNames/DICOM.html. Variable keys can be either the hexadecimal format (ID) or string format (Name). For example 0018:1030 or ProtocolName. The params object contains any number of key/value pairs.
Files associated with this section are stored in the following directory. subjectID, studyNum, seriesNum are the actual subject ID, study number, and series number. For example /data/S1234ABC/1/1.
/data/<SubjectID>/<StudyNum>/<SeriesNum>/params.json
| Variable | Description | Example |
|---|---|---|
{Key:Value}
A unique key, sometimes derived from the DICOM header
Protocol, T1w FieldStrength, 3.0
JSON array
An array of series. Basic series information is stored in the main squirrel.json file. Extended information including series parameters such as DICOM tags are stored in a params.json file in the series directory.
Files associated with this section are stored in the following directory. subjectID, studyNum, seriesNum are the actual subject ID, study number, and series number. For example /data/S1234ABC/1/1.
/data/<SubjectID>/<StudyNum>/<SeriesNum>
Behavioral data is stored in
/data/<SubjectID>/<StudyNum>/<SeriesNum>/beh
Primary key Required Computed (squirrel writer/reader should handle these variables)
| Variable | Type | Default | Description |
|---|---|---|---|
BidsEntity
string
BIDS entity (anat, fmri, dwi, etc)
BidsSuffix
string
BIDS suffix
BIDSTask
string
BIDS Task name
BIDSRun
number
BIDS run number
BIDSPhaseEncodingDirection
string
BIDS PE direction
Description
string
Description of the series
ExperimentName
string
Experiment name associated with this series. Experiments link to the experiments section of the squirrel package
Protocol
string
Protocol name
Run
number
The run identifies order of acquisition in cases of multiple identical series.
SeriesDatetime
date
Date of the series, usually taken from the DICOM header
SeriesNumber
number
Series number. May be sequential, correspond to NiDB assigned series number, or taken from DICOM header
SeriesUID
string
From the SeriesUID DICOM tag
BehavioralFileCount
number
Total number of beh files (including files in subdirs)
BehavioralSize
number
Size of beh data, in bytes
FileCount
number
Total number of files (including files in subdirs)
Size
number
Size of the data, in bytes
JSON file
data/subjectID/studyNum/seriesNum/params.json
JSON object