. Author manuscript; available in PMC: 2020 Mar 10.

Published in final edited form as: Int J Radiat Oncol Biol Phys. 2018 Oct 26;103(3):738–746. doi: 10.1016/j.ijrobp.2018.10.024

Table 3.

Four-dimensional computed tomography–ventilation heterogeneity metrics compared between patients with and without clinically diagnosed emphysema or COPD

	No emphysema/ COPD Mean ± SD	Emphysema/ COPD Mean ± SD	P value
Cohort of patients with esophageal cancer (N = 35)
CoV	0.52 ± 0.22	0.53 ± 0.13	.32
Vent-RL (%)	11.1 ± 13.6	11.3 ± 8.6	.47
Vent-SI (%)	70.1 ± 15.3	80.6 ± 8.1	.05
Cohort of patients with esophageal + lung cancer (N = 70)
CoV	0.52 ± 0.22	0.57 ± 0.17	.05
Vent-RL (%)	15.2 ± 20.0	13.2 ± 12.6	.43
Vent-SI (%)	68.8 ± 15.1	73.7 ± 11.4	.17

Abbreviations: COPD = chronic obstructive pulmonary disease; CoV = coefficient of variation; Vent-RL = right-to-left lung ventilation ratio; Vent-SI = superior-inferior ventilation.