Table 4.

Correlation between MRI and other methods

	N	SQRT (MSE)	R	P Value
MRI vs. D3-creatine
Method 1 (urine)	17	2.98	0.888	<0.0001
Method 2 (urine)	17	2.64	0.913	<0.0001
Method 3 (urine)	17	3.02	0.884	<0.0001
Method 4 (plasma)	15	3.50	0.815	0.0002
MRI vs. DXA
LBM	17	1.41	0.976	<0.0001
ALM	17	1.39	0.977	<0.0001
MRI vs. 24-h UCrn (mean of 3 days)	17	2.75	0.905	<0.0001

SQRT, square root; MSE, mean square error.