Mapping Neuroinflammation With Diffusion-Weighted Magnetic Resonance Imaging: A Randomized Crossover Study.

Area of Science:

• Neuroimaging
• Neuroinflammation
• Psychiatric Disorders

Background:

• Neuroinflammation's role in psychiatric conditions is unclear.
• Non-invasive in vivo methods are needed to measure neuroinflammation.
• Diffusion-weighted MRI was explored for detecting low-level neuroinflammation.

Purpose of the Study:

• To investigate advanced diffusion-weighted MRI techniques for detecting neuroinflammation.
• To assess potential applications in psychiatric disorders.

Main Methods:

• A randomized, placebo-controlled, crossover study with 20 healthy volunteers.
• MRI scans (diffusion tensor, diffusion kurtosis, NODDI) before and after placebo/vaccine.
• Analysis of thirteen white matter tracts and 15 grey matter regions using region-of-interest and tractography.

Main Results:

• Global reduction in mean diffusivity (MD) in white matter tracts (p=.040).
• Increased axial kurtosis in white matter (p<.001) and mean/radial kurtosis in grey matter (p=.038).
• Correlations observed between interleukin-6 (IL-6) and diffusion parameters.

Conclusions:

• Diffusion-weighted MRI is sensitive to inflammation-induced microstructural brain changes.
• This technique may help understand neuroinflammation in psychiatric disorders.
• Further research integrating complementary methods is recommended.