TY - JOUR
T1 - Longitudinal, region-specific course of diffusion tensor imaging measures in mild cognitive impairment and Alzheimer's disease
AU - Nowrangi, Milap A.
AU - Lyketsos, Constantine G.
AU - Leoutsakos, Jeannie Marie S.
AU - Oishi, Kenichi
AU - Albert, Marilyn
AU - Mori, Susumu
AU - Mielke, Michelle M.
N1 - Funding Information:
The authors thank Gwenn Smith, PhD, for review and input. This research was funded in part by grants from GlaxoSmithKline and the National Institute on Aging ( P50-AG005146 , P50-AG021334 , and R21 AG033774 ) and by grants from the National Institutes of Health ( R21AG033774 and P50AG005146 ).
PY - 2013/9
Y1 - 2013/9
N2 - Background: Diffusion tensor imaging (DTI) is a promising method for identifying significant cross-sectional differences of white-matter tracts in normal controls (NC) and those with mild cognitive impairment (MCI) or Alzheimer's disease (AD). There have not been many studies establishing its longitudinal utility. Methods: Seventy-five participants (25 NC, 25 amnestic MCI, and 25 AD) had 3-Tesla MRI scans and clinical evaluations at baseline and 3, 6, and 12 months. Fractional anisotropy (FA) and mean diffusivity (MD) were analyzed at each time-point and longitudinally in eight a priori-selected areas taken from four regions of interest (ROIs). Results: Cross-sectionally, MD values were higher, and FA values lower in the fornix and splenium of the AD group compared with either MCI or NC (P <.01). Within-group change was more evident in MD than in FA over 12 months: MD increased in the inferior, anterior cingulum, and fornix in both the MCI and AD groups (P <.01). Conclusions: There were stable, cross-sectional, region-specific differences between the NC and AD groups in both FA and MD at each time-point over 12 months. Longitudinally, MD was a better indicator of change than FA. Significant increases of fornix MD in the MCI group suggest this is an early indicator of progression.
AB - Background: Diffusion tensor imaging (DTI) is a promising method for identifying significant cross-sectional differences of white-matter tracts in normal controls (NC) and those with mild cognitive impairment (MCI) or Alzheimer's disease (AD). There have not been many studies establishing its longitudinal utility. Methods: Seventy-five participants (25 NC, 25 amnestic MCI, and 25 AD) had 3-Tesla MRI scans and clinical evaluations at baseline and 3, 6, and 12 months. Fractional anisotropy (FA) and mean diffusivity (MD) were analyzed at each time-point and longitudinally in eight a priori-selected areas taken from four regions of interest (ROIs). Results: Cross-sectionally, MD values were higher, and FA values lower in the fornix and splenium of the AD group compared with either MCI or NC (P <.01). Within-group change was more evident in MD than in FA over 12 months: MD increased in the inferior, anterior cingulum, and fornix in both the MCI and AD groups (P <.01). Conclusions: There were stable, cross-sectional, region-specific differences between the NC and AD groups in both FA and MD at each time-point over 12 months. Longitudinally, MD was a better indicator of change than FA. Significant increases of fornix MD in the MCI group suggest this is an early indicator of progression.
KW - Alzheimer's disease
KW - Anisotropy
KW - DTI
KW - Diffusivity
KW - Longitudinal
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U2 - 10.1016/j.jalz.2012.05.2186
DO - 10.1016/j.jalz.2012.05.2186
M3 - Article
C2 - 23245561
AN - SCOPUS:84883552729
SN - 1552-5260
VL - 9
SP - 519
EP - 528
JO - Alzheimer's and Dementia
JF - Alzheimer's and Dementia
IS - 5
ER -