def adjust_for_perfusion(volume, cbf, coef=0.8, exp=0.5, tissue_density=1.041):
    """
    use Grubb's relationship to adjust a tissue volume
    that accounts for CBV (calulation from CBF)

    Parameters
    ----------
    volume : float
        The original volume of tissue.
    cbf : float
        the cererebral blood flow in ml/100g/min.
    coef : float, optional
        Grubb's coefficient. The default is 0.8.
    exp : float, optional
        Grubb's exponent. The default is 0.5.
    tissue_density : float, optional
        The tissue density, in g/cc
        https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0404.1970.tb05606.x#:~:text=Data%20obtained%20in%20this%20investigation,grams%20per%20cubic%20centimeter%20(S.E.

    Returns
    -------
    The tissue volume, adjusted to account for the fact that some of the tissue 
    was actually blood.

    """
    cbv = coef * cbf ** exp # cbv in ml/100g tissue
    blood_frac = (cbv * tissue_density)/100  # ml / 100cc (dimensionless)
    adjusted = volume * (1-blood_frac)
    return adjusted