Correlation of the fractional changes (FC; %) of parameters with multi-slice CT lung volumes. Regression lines with 95% individual confidence intervals.(a) Insignificant correlation of arterial partial oxygen pressure (PaO2) with nonaerated lung. Note the large confidence intervals. (b) Insignificant correlation of venous admixture (QVA/QT) with nonaerated lung. (c) Close relation between changes in plateau pressure (PPLAT) and poorly aerated lung. (d) Pressure of maximum compliance increase on inflation curve (Pmci) correlates non-linearly with aerated volume (volume of normally aerated lung parenchyma (VNORM) + volume of poorly aerated lung parenchyma (VPOOR)). Note the sharp increase of Pmci beyond 20% increase in aerated lung volume.