TY - JOUR
T1 - Age-related microstructural differences quantified using myelin water imaging and advanced diffusion MRI
AU - Billiet, T.
AU - Vandenbulcke, M.
AU - Mädler, B.
AU - Peeters, R.
AU - Dhollander , T.
AU - Zhang, H.
AU - Deprez, S.
AU - Van Den Bergh, B.R.H.
AU - Sunaert, S.
AU - Emsell, L.
PY - 2015
Y1 - 2015
N2 - Age-related microstructural differences have been detected using diffusion tensor imaging (DTI). Although DTI is sensitive to the effects of aging, it is not specific to any underlying biological mechanism, including demyelination. Combining multiexponential T2 relaxation (MET2) and multishell diffusion MRI (dMRI) techniques may elucidate such processes. Multishell dMRI and MET2 data were acquired from 59 healthy participants aged 17–70 years. Whole-brain and regional age-associated correlations of measures related to multiple dMRI models (DTI, diffusion kurtosis imaging [DKI], neurite orientation dispersion and density imaging [NODDI]) and myelin-sensitive MET2 metrics were assessed. DTI and NODDI revealed widespread increases in isotropic diffusivity with increasing age. In frontal white matter, fractional anisotropy linearly decreased with age, paralleled by increased “neurite” dispersion and no difference in myelin water fraction. DKI measures and neurite density correlated well with myelin water fraction and intracellular and extracellular water fraction. DTI estimates remain among the most sensitive markers for age-related alterations in white matter. NODDI, DKI, and MET2 indicate that the initial decrease in frontal fractional anisotropy may be due to increased axonal dispersion rather than demyelination.Keywords: Aging, Relaxometry, Myelin water imaging, Diffusion MRI, Healthy,Kurtosis
AB - Age-related microstructural differences have been detected using diffusion tensor imaging (DTI). Although DTI is sensitive to the effects of aging, it is not specific to any underlying biological mechanism, including demyelination. Combining multiexponential T2 relaxation (MET2) and multishell diffusion MRI (dMRI) techniques may elucidate such processes. Multishell dMRI and MET2 data were acquired from 59 healthy participants aged 17–70 years. Whole-brain and regional age-associated correlations of measures related to multiple dMRI models (DTI, diffusion kurtosis imaging [DKI], neurite orientation dispersion and density imaging [NODDI]) and myelin-sensitive MET2 metrics were assessed. DTI and NODDI revealed widespread increases in isotropic diffusivity with increasing age. In frontal white matter, fractional anisotropy linearly decreased with age, paralleled by increased “neurite” dispersion and no difference in myelin water fraction. DKI measures and neurite density correlated well with myelin water fraction and intracellular and extracellular water fraction. DTI estimates remain among the most sensitive markers for age-related alterations in white matter. NODDI, DKI, and MET2 indicate that the initial decrease in frontal fractional anisotropy may be due to increased axonal dispersion rather than demyelination.Keywords: Aging, Relaxometry, Myelin water imaging, Diffusion MRI, Healthy,Kurtosis
U2 - 10.1016/j.neurobiolaging.2015.02.029
DO - 10.1016/j.neurobiolaging.2015.02.029
M3 - Article
SN - 0197-4580
VL - 36
SP - 2107
EP - 2121
JO - Neurobiology of Aging
JF - Neurobiology of Aging
IS - 6
ER -