OMICS 放射線学ジャーナル

抽象的な

Age-related Changes of White Matter in the Elderly Population Measured by Diffusion Tensor Imaging

Sheng-Heng Tsa, Jachih Fu, Jyh-Wen Chai, Yi-Ying Wu1 and Clayton Chi-Chang Chen

Background: A decline in cerebral White Matter (WM) integrity occurs across the adult lifespan, with more rapid degradation later in life. Diffusion Tensor Imaging (DTI) is a non-invasive method to evaluate the microscopic changes of WM in vivo. Linear regression models have been applied to depict the relationship between diffusion properties, such as Fractional Anisotropy (FA) and Mean Diffusivity (MD), derived from DTI and age. However, the fit of these linear regression models is unsatisfactory.

Objectives: The purpose of our study was to investigate the age-related changes of WM in an elderly population.

Methods: We performed statistical parametric mapping with DTI to evaluate the patterns of age-related microscopic WM changes with voxel-based analysis in the elderly population (>55 years old). A linear regression model was used to examine the associations between DTI parameters and age.

Results: The fit of the linear regression model depicting the association between mean global FA, MD values (FA, MD derived from global WM), and age was better than that reported in prior studies using DTI (R2=0.4252, p<0.001 for global FA and age; R2=0.5309, p<0.001 for global MD and age). Moreover, comparable to previous studies, the mean global FA showed a significant negative correlation with mean global MD, indicating a true age-related phenomenon of increased interstitial or intracellular fluid accumulation in cerebral WM. The mean frontal FA value was significantly lower than the mean global FA value. However, there was no significant difference between the mean frontal MD value and the mean global MD value.

Conclusions: Focusing on the elderly population, we can improve the fit of linear regression models to investigate the age-related changes of WM by DTI. These results suggest that age-related microscopic changes of WM might be occurring more consistently in later life.