Visualizing functional pathways in the human brain using correlation tensors and magnetic resonance imaging

Area of Science:

• Neuroimaging
• White Matter Tracts
• Functional MRI

Background:

• Functional magnetic resonance imaging (fMRI) typically detects blood oxygenation level dependent (BOLD) signals in the brain cortex.
• Resting-state fMRI has shown structure-specific temporal correlations along white matter tracts.

Observation:

• This study validates preliminary findings on resting-state MRI signals in white matter.
• Spatio-temporal functional correlation tensors are introduced to characterize directional preferences of temporal correlations in resting-state MRI signals.

Findings:

• Resting-state functional correlation tensors reveal white matter tract structures without diffusion-encoding gradients, similar to diffusion tensor imaging.
• These tensors visualize both long-range white matter tracts and short-range sub-cortical fibers.
• Evoked functional activities modify these structures, enhancing relevant neural circuitry visualization.

Implications:

• Temporal correlations in resting-state signals may indicate intrinsic neural activity synchronizations within white matter.
• White matter signal variations are consistent with hemodynamic (BOLD) changes linked to neural activity.
• The study proposes novel approaches for assessing MRI signal alterations in white matter.