def get_util_shape(row):
    """Get utility term shape based on ROI.

    Parameters
    ----------
    row : pandas.core.series.Series
        Row of func_df DataFrame.

    Returns
    -------
    str
        If 'chest' or 'rib in row['Roi'], then return 'linear'.
        Otherwise, return 'linear_quadratic'.

    """
    if any([roi in row['Roi'].lower() for roi in ['chest', 'rib']]):
        return 'linear'
    return 'linear_quadratic'