Read NIFTI v2 header from file.
Value
named list with NIFTI 2 header fields. The header extensions, if the file has any, are returned in
the field extensions, a list in which each entry is one header extension as created by
nifti2.extension (i.e., a list with the entries 'ecode' and 'content'). CIFTI2 files store
their XML metadata in such an extension, see nifti2.get.extension.