def lookForMetadataElements(fileDataset, pattern):
    """Find the DICOM keywords that match the 'str' string.

    Parameters
    ----------
    fileDataset : pydicom.dataset.FileDataset
        Image and metadata

    pattern : str
        String pattern to look for in the metadata

    Returns
    -------
         : list
        List of DICOM keyword (tags) that match the pattern.
    """

    return fileDataset.dir(pattern)