Fig. 3

The linear diaphragm position and lung signal correlation. The correlation between the relative diaphragm position and the average lung ventilation signal of each frame are exemplarily shown for a scan of the aorta (A) and lung slice (B). As a reference for the diaphragm positions, the mid position between full inspiration and full expiration was used, meaning that positive values describe the increase in lung volume and consequently negative values the decrease in lung volume. Regardless of the considered slice, a linear relationship between the two quantities is observable. The slope of the linear fit function depicted in red finds application in Eq. 1