Table 3.

Summary of whole-lung and regional comparisons. Systematic bias refers to the mean difference between single-breath and dedicated measurements. All other values are shown as mean (range).

Comparison	Ventilation	Membrane	RBC
Systematic Bias (Bland Altman Analysis)	−2 percentage points	−0.028	−0.013
Structural Similarity	0.52 (0.38 – 0.62)	0.71 (0.65 – 0.79)	0.14 (0.07 – 0.23)
PSNR	22.3 (20.2 – 24.3)	25.3 (24.7 – 26.3)	20.3 (17.7 – 22.5)

Comparison	Normal Ventilation	Ventilation Defects	Normal Membrane	Low Membrane	Normal RBC	Low RBC
Dice Coefficient	0.92 (0.88 – 0.94)	0.27 (0.02 – 0.69)	0.82 (0.73 – 0.90)	0.40 (0.09 – 0.59)	0.73 (0.58 – 0.80)	0.60 (0.54 – 0.69)
Average Distance	0.08 (0.05 – 0.13)	4.94 (0.52 – 14.01)	0.19 (0.10 – 0.29)	1.5 (0.6 – 4.49)	0.33 (0.24 – 0.55)	0.50 (0.39 – 0.60)