Age-related white matter changes in high b-value q-space diffusion-weighted imaging

Area of Science:

• Neuroimaging
• Radiology
• Gerontology

Background:

• Age-related changes in white matter are a significant concern in neuroscience.
• Diffusion-weighted imaging (DWI) and q-space imaging (QSI) are advanced MRI techniques used to study white matter integrity.

Purpose of the Study:

• To compare the sensitivity of DWI and QSI in quantifying age-related diffusion changes in the white matter of different cerebral lobes.
• To assess how white matter diffusion characteristics change with age across the frontal, parietal, and temporal lobes.

Main Methods:

• Seventy-three neurologically healthy individuals were categorized into four age groups: young, middle-aged, old, and very old.
• Magnetic resonance imaging (MRI) using a 1.5-T scanner was performed for DWI and QSI.
• Apparent diffusion coefficient (ADC) from DWI and mean displacement (MDP) from QSI were calculated for white matter in the frontal, parietal, and temporal lobes.

Main Results:

• Mean displacement (MDP) values, indicative of white matter changes, were significantly higher in older age groups (old and very old) in the frontal and parietal lobes, and in the very old group in the temporal lobes.
• Apparent diffusion coefficient (ADC) values were significantly elevated in all three lobes in the very old group compared to the young group.
• These findings suggest differential age-related diffusion changes across cerebral lobes.

Conclusions:

• QSI, measuring mean displacement (MDP), is more sensitive than DWI, measuring apparent diffusion coefficient (ADC), in detecting age-related myelin loss in white matter.
• The study highlights the utility of QSI for a more nuanced assessment of white matter aging.