Table 2:

Quantitative measurements of normal-appearing white matter and enhancing and nonenhancing MS lesions before gadolinium-based contrast agent injection^{^a}

	R₁ (1/s)	R₂ (1/s)	PD (%)
NAWM (n = 102)	1.71 ± 0.09	13.1 ± 0.67	62.4 ± 1.9
Enhancing lesions (n = 43)	1.22 ± 0.36	9.8 ± 2.6	77.0 ± 11.2
Nonenhancing lesions (n = 622)	0.89 ± 0.24	7.4 ± 1.9	89.8 ± 8.4
Difference between enhancing and nonenhancing lesions	+0.33^{^b}	+2.43^{^b}	−12.8^{^b}

↵a Data are means. Differences are estimated as least squares means and are tested with the Tukey t test.
↵b P < .001.