def load_volume_maps(directory, map_names=None, deferred=True):
    """Read a number of Nifti volume maps from a directory.

    Args:
        directory (str): the directory from which we want to read a number of maps
        map_names (list or tuple): the names of the maps we want to use. If given we only use and return these maps.
        deferred (boolean): if True we return an deferred loading dictionary instead of a dictionary with the values
            loaded as arrays.

    Returns:
        dict: A dictionary with the volumes. The keys of the dictionary are the filenames (without the extension) of the
            files in the given directory.
    """
    from mdt.lib.nifti import get_all_nifti_data
    return get_all_nifti_data(directory, map_names=map_names, deferred=deferred
        )
