NIfTI metadata extension

The current NIfTI header definition does not contain enough metadata to completely describe a dataset. We propose a NIfTI header extension that is a JSON object using NeuroLex ID's as the field names, with values stored as strings (as per the JSON standard). We need a machine-readable JSON schema that defines the specific NeuroLex terms that may be included, the data types (e.g., int, float, array, ...), and the common human-readable names. This schema should be maintained and hosted by the NIF/INCF.

We propose to structure the JSON object like this: