Table 2.

Correlation coefficients between US and CT methods in all, young, and older participants

Relationship	r	P-value
Between MT and CSA
All (n=40, 80 legs)	0.774	<0.001
Young (n=19, 38 legs)	0.736	<0.001
Older (n=21, 42 legs)	0.574	<0.001
Between EI and CT value
All (n=40, 80 legs)	−0.524	<0.001
Young (n=19, 38 legs)	−0.458	0.004
Older (n=21, 42 legs)	−0.363	0.018
Between EI and %LDMA
All (n=40, 80 legs)	0.460	<0.001
Young (n=19, 38 legs)	0.397	0.014
Older (n=21, 42 legs)	0.257	0.100

Notes: The relationship between EI and CT value and between EI and %LDMA in all participants are shown by a quadratic regression curve. Others are a linear regression.

Abbreviations: CSA, cross-sectional area of muscle; CT, computed tomography; EI, echo intensity; MT, muscle thickness of front thigh; US, ultrasonography; %LDMA, percentage of low-density muscle area.