Two-dimensional shear wave elastography: a new tool for evaluating respiratory muscle stiffness in chronic obstructive pulmonary disease patients

Table 7 Correlation between the ultrasonic indicators and lung volume in COPD

	RV		TLC		RV/TLC		FRC		IC
	r	P	r	P	r	P	r	P	r	P
Elastic modulus of diaphragm	0.65	< 0.001	0.54	< 0.001	0.60	< 0.001	0.72	< 0.001	-0.41	< 0.001
Elastic modulus of intercostal muscle	0.54	< 0.001	0.47	< 0.001	0.48	0.001	0.60	< 0.001	-0.33	< 0.001
DE at tidal inspiration	-0.54	< 0.001	-0.37	< 0.001	-0.53	< 0.001	-0.48	< 0.001	0.26	< 0.001
DE at maximal deep inspiration	-0.02	0.771	-0.06	0.406	-0.01	0.913	-0.12	0.076	0.10	0.140
TF at tidal inspiration	-0.52	< 0.001	-0.26	0.019	-0.58	< 0.001	-0.48	< 0.001	0.37	< 0.001
TF at maximal deep inspiration	-0.58	< 0.001	-0.45	< 0.001	-0.55	< 0.001	-0.56	< 0.001	0.29	< 0.001

COPD chronic obstructive pulmonary disease, RV residual volume, TLC total lung capacity, FRC functional residual capacity, IC inspiratory capacity, DE diaphragm excursion, TF thickening fraction

ISSN: 1471-2466