Figure 5.

Comparison of end expiratory lung volume (EELV) measured by the helium dilution technique and the nitrogen washout/washin method. (a) The EELV measured by the helium dilution as a function of the EELV measured by nitrogen washout/washin method (EELV helium dilution = (290 + 0.92) × EELV GE, r² = 0.82, p < 0.00001). (b) The Bland-Altman plot of the EELV measured with the nitrogen washout/washin technique and the EELV measured with the helium dilution method. The x axis shows the mean of the two measurements and the y axis shows the difference between the EELV measured by then helium dilution method and the nitrogen washoutwashin measured by the CT scan (average difference -229 ± 164 ml, limits of agreement -558 – 100 ml).