A. Pfefferbaum et al., Age-related decline in brain white matter anisotropy measured with spatially corrected echo-planar diffusion tensor imaging, MAGN RES M, 44(2), 2000, pp. 259-268
Citations number
41
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Medical Research Diagnosis & Treatment
Echo planar (EP) diffusion tensor imaging (DTI) permits in vivo identificat
ion of the orientation and coherence of brain white matter tracts but suffe
rs from field inhomogeneity-induced geometric distortion. To reduce spatial
distortion, polynomial warping corrections were applied and the effects te
sted on measures of fractional anisotropy (FA) in the genu and splenium of
corpus callosum. Implementation entailed spatially warping EP images obtain
ed without diffusion weighting (b = 0) to long-echo T-2-weighted fast spin
echo images, collected for anatomical delineation, tissue segmentation, and
coregistration with the diffusion images. Using the optimal warping proced
ure (third-order polynomial), the effects of age on FA and a quantitative m
easure of intervoxel coherence (C) in the genu, splenium, centrum semiovale
, and frontal and parietal pericallosal white matter were examined in 31 he
althy men (23-76 years). FA declined significantly with age in all regions
except the splenium, whereas intervoxel coherence positively correlated wit
h age in the genu. Magn Reson Med 44:259-268, 2000. (C) 2000 Wiley-Liss, In
c.