readNifti(file, internal = FALSE)FALSE (the default), an array
of class "niftiImage", containing the image pixel or voxel values,
will be returned. If TRUE, the return value will be an object of
class "internalImage", which contains only minimal metadata about
the image. Either way, the return value has an attribute which points to a
C data structure containing the full image."niftiImage", and
possibly also "internalImage".
writeNifti