. Author manuscript; available in PMC: 2018 Feb 1.

Published in final edited form as: Respir Med. 2016 Nov 25;123:48–55. doi: 10.1016/j.rmed.2016.11.021

Table 2.

Spearman’s Rho correlation coefficients between CT-metrics (PRM^Emph, PRM^fSAD, Perc15, and E/I-ratio_MLD) and clinical parameters. All correlation coefficients were statistically significant (all p < 0.001).

	FEV₁% predicted	FEV₁/FVC	FEV₁/VC	RV/TLC	KCO
PRM^Emph	−0.763	−0.858	−0.862	0.770	−0.797
PRM^fSAD	−0.724	−0.819	−0.827	0.779	−0.752
Perc15	0.572	0.636	0.632	−0.503	0.523
E/I-ratio_MLD	−0.645	−0.723	−0.730	0.736	−0.677

PRM^Emph: extent of emphysema as determined by parametric response mapping; extent of small airway disease as determined by parametric response mapping; Perc15: emphysema score as 15th percentile of attenuation distribution curve on inspiratory scan; E/I-ratio_MLD: expiration to inspiration ratio of mean lung density.