TABLE 1:

Mean values (± SD) for fractional anisotropy and coefficient D_av in the various investigated white matter brain regions

	FA	Dav (×10−3 mm2/s)
All plaques (n = 76)	0.22 ± 0.07	1.54 ± 0.33
NAWM regions (n=76)	0.32 ± 0.09	1.00 ± 0.14
NWM regions (n=76)	0.37 ± 0.09	0.89 ± 0.08

Note.—FA indicates fractional anisotropy; D_av, average diffusivity; NAWM, normal appearing white matter; NWM, normal white matter. Note that FA is expressed as a unitless number that may range from 0 to 1 and that D_av is equal to one-third of the trace of the diffusion tensor.

The P value was <.001 for all paired t tests between groups (plaques and NAWM regions, plaques and NWM regions, NAWM and NWM regions).