Longitudinal analyses revealed statistically significant relationships between liver volume change and liver mean PDFF change ( R 2 = 0.556 , P < 0.001 ) , between TLFI change and liver mean PDFF change ( R 2 = 0.920 , P < 0.001 ) , and between TLFI change and liver volume change ( R 2 = 0.735 , P < 0.001 ) .