Modeling white matter tract integrity in aging with diffusional kurtosis imaging

NEUROBIOLOGY OF AGING

卷:70

Article

Benitez, Andreana^1,2,3  Jensen, Jens H.^1,3,4  Falangola, Maria Fatima^1,3,4  Nietert, Paul J.⁵  Helpern, Joseph A.^1,2,3,4 

[1] Med Univ South Carolina, Ctr Biomed Imaging, 96 Jonathan Lucas St,MSC 606, Charleston, SC 29425 USA

[2] Med Univ South Carolina, Dept Neurol, Charleston, SC 29425 USA

[3] Med Univ South Carolina, Dept Radiol & Radiol Sci, Charleston, SC 29425 USA

[4] Med Univ South Carolina, Dept Neurosci, Charleston, SC 29425 USA

[5] Med Univ South Carolina, Dept Publ Hlth Sci, Charleston, SC 29425 USA

关键词: Aging;    White matter;    White matter tract integrity;    Diffusion MRI;    Diffusional kurtosis imaging;   

DOI  :  10.1016/j.neurobiolaging.2018.07.006

来源: Elsevier

【 摘 要 】

Myelin breakdown and neural fiber loss occur in aging. This study used white matter tract integrity metrics derived from biophysical modeling using Diffusional Kurtosis Imaging to assess loss of myelin (i.e., extraaxonal diffusivity, radial direction, De, t) and axonal density (i.e., axonal water fraction) in cognitively unimpaired older adults. Tract-based spatial statistics and region of interest analyses sought to identify ontogenic differences and age-related changes in white matter tracts using cross-sectional and longitudinal data analyzed with general linear and mixed-effects models. In addition to pure diffusion parameters (i.e., fractional anisotropy, mean diffusivity, mean kurtosis), we found that white matter tract integrity metrics significantly differentiated early-from late-myelinating tracts, correlated with age in spatially distinct regions, and identified primarily extraaxonal changes over time. Percent metric changes were [0.3-0.9]% and [0.0-1.9]% per year using cross-sectional data and longitudinal data, respectively. There was accelerated decline in some late-versus early-myelinating tracts in older age. These results demonstrate that these metrics may inform further study of the transition from age-related changes to neurodegenerative decline. (C) 2018 Elsevier Inc. All rights reserved.

【 授权许可】

Free