Table 3.

Univariable analysis of various quantitative CT features with baseline DL_CO (top) and K_CO (bottom)

Pulmonary function test	CT pattern	Number of subjects	Beta coefficient	95% CI	P‐value	R2
DLCO	Total lung volume (L)	139	3.46	1.68, 5.25	0.0002	0.10
	Mean lung attenuation (HU)	139	−0.11	−0.14, −0.08	<1 × 10−6	0.25
	Normalized vessel volume (%)	139	−5.43	−7.90, −2.96	3 × 10−5	0.12
	Normalized arterial volume (%)	96	−9.48	−14.74, −4.23	0.001	0.12
	Normalized venous volume (%)	96	−8.06	−14.65, −1.47	0.02	0.06
	Vessel density (vess/L)	139	−0.05	−0.07, −0.03	<1 × 10−6	0.17
	Arterial density (vess/L)	96	−0.08	−0.13, −0.03	0.001	0.11
	Venous density (vess/L)	96	−0.08	−0.13, −0.02	0.008	0.07
	Vessel heterogeneity (1)	139	−397.93	−755.89, −39.97	0.03	0.03
	Arterial heterogeneity (1)	96	−221.35	−599.12, 156.42	0.25	0.01
	Venous heterogeneity (1)	96	−203.23	−629.48, 223.02	0.35	0.01
KCO	Total lung volume (L)	139	3.85	−6.53, −1.17	0.005	0.06
	Mean lung attenuation (HU)	139	0.02	−0.03, 0.07	0.47	0.00
	Normalized vessel volume (%)	139	1.99	−1.86, 5.85	0.31	0.01
	Normalized arterial volume (%)	96	0.95	−7.41, 9.31	0.82	0.01
	Normalized venous volume (%)	96	5.74	−4.33, 15.82	0.26	0.01
	Vessel density (vess/L)	139	−0.02	−0.05, 0.01	0.24	0.01
	Arterial density (vess/L)	96	−0.00	−0.08, 0.07	0.96	0.00
	Venous density (vess/L)	96	−0.00	−0.08, 0.09	0.94	0.00
	Vessel heterogeneity (1)	139	−136.95	−671.13, 397.24	0.61	0.00
	Arterial heterogeneity (1)	96	−125.38	−692.96, 442.20	0.66	0.00
	Venous heterogeneity (1)	96	219.99	−417.98, 857.96	0.69	0.01

CT, computed tomography; DL_CO, diffusion capacity for carbon monoxide; HU, Hounsfield Unit; K_CO, transfer factor for carbon monoxide.