def get_additional_metadata_czi(metadatadict_czi):
    """
    Returns a dictionary with additional CZI metadata.

    :param metadatadict_czi: complete metadata dictionary of the CZI image
    :type metadatadict_czi: dict
    :return: additional_czimd - dictionary with additional CZI metadata
    :rtype: dict
    """

    additional_czimd = {}

    try:
        additional_czimd['Experiment'] = metadatadict_czi['ImageDocument']['Metadata']['Experiment']
    except KeyError as e:
        print('Key not found :', e)
        additional_czimd['Experiment'] = None

    try:
        additional_czimd['HardwareSetting'] = metadatadict_czi['ImageDocument']['Metadata']['HardwareSetting']
    except KeyError as e:
        print('Key not found :', e)
        additional_czimd['HardwareSetting'] = None

    try:
        additional_czimd['CustomAttributes'] = metadatadict_czi['ImageDocument']['Metadata']['CustomAttributes']
    except KeyError as e:
        print('Key not found :', e)
        additional_czimd['CustomAttributes'] = None

    try:
        additional_czimd['DisplaySetting'] = metadatadict_czi['ImageDocument']['Metadata']['DisplaySetting']
    except KeyError as e:
        print('Key not found :', e)
        additional_czimd['DisplaySetting'] = None

    try:
        additional_czimd['Layers'] = metadatadict_czi['ImageDocument']['Metadata']['Layers']
    except KeyError as e:
        print('Key not found :', e)
        additional_czimd['Layers'] = None

    return additional_czimd