Table 3.

Lung quantification results

Item	Mean ± SD; median; 95%CI; range	t test	Bias ± SD; 95%LOA
Lung mean density (g/cm3)
Diagnostic CT
Right lung	0.215 ± 0.049; 0.201; 0.197 to 0.232; 0.121 to 0.376
Left lung, compared to right	0.217 ± 0.054; 0.201; 0.197 to 0.236; 0.128 to 0.383	p = 0.44	+0.0019 ± 0.0131; −0.0239 to +0.0276
Mean of both lungs	0.216 ± 0.051; 0.206; 0.197 to 0.234; 0.125 to 0.379
SPECT/CT
Right lung	0.291 ± 0.051; 0.289; 0.273 to 0.309; 0.180 to 0.410
Left lung, compared to right	0.306 ± 0.064; 0.310; 0.273 to 0.309; 0.161 to 0.442	p = 0.002	+0.0152 ± 0.0243; −0.0324 to +0.0628
Mean of both lungs, compared to diagnostic CT	0.299 ± 0.056; 0.298; 0.278 to 0.319; 0.171 to 0.417	p <0.001
Lung parenchyma mass (g)
Diagnostic CT
All patients	822 ± 103; 809; 785 to 859; 621 to 1,107
Male	828 ± 114; 823; 783 to 874; 621 to 1,107
Female	795 ± 19; 801; 780 to 811; 764 to 812
SPECT/CT
All patients, compared to diagnostic CT	788 ± 110; 736; 748 to 827; 624 to 1,045	p = 0.19	−21.7 ± 88.2; −194.6 to +151.2
Lung volume (cm3)
Diagnostic CT	3,967 ± 798; 4,049; 3,682 to 4,253; 2,142 to 5,634
SPECT/CT, compared to diagnostic CT	2,749 ± 744; 2,530; 483 to 3,015; 1,698 to 5,199	p <0.001
Lung shunt fraction (%)
SPECT/CT	5.96 ± 4.59; 4.97; 4.32 to 7.61; 0.98 to 21.71
Planar, compared to SPECT/CT	7.36 ± 4.96; 6.03; 5.58 to 9.14; 2.20 to 25.26	p <0.001	+1.40 ± 1.60; −1.73 to +4.52
Lung Dmean (Gy)
Reference Dmean	6.16 ± 5.24; 3.64; 4.28 to 8.03; 0.76 to 17.52
Planar, compared to reference	6.07 ± 4.51; 4.75; 4.46 to 7.68; 1.00 to 16.02	p = 0.78	−0.09 ± 1.73; −3.48 to +3.31
SPECT/CT, compared to reference	6.48 ± 5.51; 4.06; 4.51 to 8.45; 0.85 to 18.87	p = 0.11	+0.32 ± 1.06; −1.76 to +2.40
Planar, compared to SPECT/CT		p = 0.27	−0.41 ± 2.00; −4.32 to +3.50