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. 2010 Oct 4;588(Pt 23):4759–4768. doi: 10.1113/jphysiol.2010.196063

Figure 2. Mean ±s.d. density (top) and perfusion (bottom) vs. distance from the most dependent portion of the lung.

Figure 2

Note that the x and y axes have been reversed in these figures so that vertical height increases up the figure. Data are for all 3 lung slices in 7 subjects and were averaged for all voxels lying within the same vertical (isogravitational) plane at 1 cm increments. There is only a small difference between RV and FRC, consistent with the lung volume changes described above. The density is markedly less at TLC compared to FRC or RV, consistent with the greater air volume of the lung at TLC. The perfusion distributions are largely similar between lung volumes. At TLC, the perfusion distribution although similar to RV and FRC over most of the vertical height, is less in the most non-dependent lung, but this difference is only significant (P < 0.05) at heights above 11.5 cm. The height of maximum perfusion was not different between lung volumes, nor was the slope of the relationship between perfusion and vertical height above this point. Statistical details are given in Table 2.