def _imagej_description(version='1.11a', **kwargs):
    """ Return a string that will be used by ImageJ to read the unit when
        appropriate arguments are provided """
    result = ['ImageJ=%s' % version]
    append = []
    if kwargs['spacing'] is None:
        kwargs.pop('spacing')
    for key, value in list(kwargs.items()):
        if value == 'µm':
            value = 'micron'
        append.append('%s=%s' % (key.lower(), value))
    return '\n'.join(result + append + [''])
