Reproducibility of color Doppler imaging

For EDV and PSV, considered effect sizes are differences between parallel groups in pre-post ratio of the means. For example, suppose that the ratio between the pre- and post condition in the first group is c times higher than in the second group; this implies a difference in change of ln(c) on the log-scale. With y ₀ and y ₁ the pre- and post-measurement in one group and x ₀ and x ₁ the pre- and post-measurement in the other group: \( \left\{ {\ln \left( {y_1} \right) - \ln \left( {y_0} \right)} \right\} - \left\{ {\ln \left( {x_1} \right) - \ln \left( {x_0} \right)} \right\} = \ln \left( {{{y_1} \mathord{\left/{\vphantom {{y_1} {y_0}}} \right.} {y_0}}} \right) - \ln \left( {{{x_1} \mathord{\left/{\vphantom {{x_1} {x_0}}} \right.} {x_0}}} \right) = \ln \left( {\frac{{{{y_1} \mathord{\left/{\vphantom {{y_1} {y_0}}} \right.} {y_0}}}}{{{{x_1} \mathord{\left/{\vphantom {{x_1} {x_0}}} \right.} {x_0}}}}} \right) \). For c= 1.05, 1.10, 1.15 and 1.20, the difference in changes on the log-scale are 0.049, 0.095, 0.140 and 0.182 respectively.