Detailed Mapping of the Cerebellar Dentate Nucleus Using Ultra-High Field (7T) Susceptibility-Weighted Imaging

Area of Science:

• Neuroimaging
• Neuroanatomy
• Cerebellar Neuroscience

Background:

• The cerebellar dentate nucleus, crucial for motor control and cognition, has complex subregions that are challenging to delineate.
• Existing imaging techniques lack the resolution to reliably segment dentate subregions, limiting functional studies.

Purpose of the Study:

• To develop and validate a novel imaging method for segmenting the cerebellar dentate nucleus and its subregions.
• To investigate the distinct functional connectivity (FC) patterns of the dorsal and ventral dentate subregions.

Main Methods:

• Utilized ultra-high field (7T) MRI and quantitative susceptibility mapping (QSM) for high-resolution imaging of the dentate nucleus.
• Assessed segmentation reliability using inter-rater and intra-rater Dice coefficients.
• Evaluated functional connectivity (FC) of dorsal and ventral dentate subregions using resting-state fMRI in neurotypical adults.

Main Results:

• Achieved high segmentation reliability (inter-rater d=0.89, intra-rater d=0.93).
• The dorsal dentate subregion was significantly smaller than the ventral subregion (p < .001).
• Dorsal dentate exhibited greater FC with sensorimotor regions, while the ventral dentate showed greater FC with cognitive processing regions.

Conclusions:

• Presented an innovative, reliable, and valid method for imaging the cerebellar dentate nucleus and its subregions.
• Demonstrated distinct functional connectivity profiles for dorsal (sensorimotor) and ventral (cognitive) dentate subregions.
• The findings support future applications in clinical populations with cerebellar abnormalities.