PURPOSE: We applied a novel diffusion spectrum imaging (DSI) acquisition to determine associations between aging and subcortical fiber tract integrity. MATERIALS AND METHODS: We studied 35 cognitively healthy subjects (17 women), spanning the adult age range between 23 and 77 years, using anatomical MRI and a novel DSI acquisition scheme at 3 Tesla. The study was approved by the local institutional review board. DSI data were analyzed using tractography and complementary voxel-based analysis of generalized fractional anisotropy (GFA) maps. We determined the effects of age on generalized fractional anisotropy in selected fiber tracts as well as in a whole brain voxel-based analysis. For comparison, we studied the effects of age on regional gray and white matter volumes. RESULTS: We found a significant reduction in anterior corpus callosum fiber tract integrity with age (P < 0.001), as well as significant GFA reduction throughout the subcortical white matter (P < 0.05, false discovery rate [FDR] corrected). GFA decline was accompanied by significant gray matter atrophy in frontal and temporal association cortex (P < 0.05, FDR corrected). CONCLUSION: Our data suggest that normal aging leads to a regionally specific decline in fiber tract integrity. DSI may become a useful biomarker in healthy and pathological aging.
PURPOSE: We applied a novel diffusion spectrum imaging (DSI) acquisition to determine associations between aging and subcortical fiber tract integrity. MATERIALS AND METHODS: We studied 35 cognitively healthy subjects (17 women), spanning the adult age range between 23 and 77 years, using anatomical MRI and a novel DSI acquisition scheme at 3 Tesla. The study was approved by the local institutional review board. DSI data were analyzed using tractography and complementary voxel-based analysis of generalized fractional anisotropy (GFA) maps. We determined the effects of age on generalized fractional anisotropy in selected fiber tracts as well as in a whole brain voxel-based analysis. For comparison, we studied the effects of age on regional gray and white matter volumes. RESULTS: We found a significant reduction in anterior corpus callosum fiber tract integrity with age (P < 0.001), as well as significant GFA reduction throughout the subcortical white matter (P < 0.05, false discovery rate [FDR] corrected). GFA decline was accompanied by significant gray matter atrophy in frontal and temporal association cortex (P < 0.05, FDR corrected). CONCLUSION: Our data suggest that normal aging leads to a regionally specific decline in fiber tract integrity. DSI may become a useful biomarker in healthy and pathological aging.
Authors: Nikki H Stricker; David H Salat; Taylor P Kuhn; Jessica M Foley; Jenessa S Price; Lars T Westlye; Michael S Esterman; Regina E McGlinchey; William P Milberg; Elizabeth C Leritz Journal: Am J Alzheimers Dis Other Demen Date: 2015-04-22 Impact factor: 2.035