Taking cerebellar segmentations to the next level: 100µm resolution at 9.4T

Motivation: At common spatial resolutions (±0.7-1mm), cerebellar segmentation cannot delineate smaller white matter branches. Previous work recommended ~200um voxels for cerebellar cortex delineation. Goal(s): To test whether higher resolution imaging results in a more accurate segmentation of cerebellar grey/white matter. Approach: A post-mortem human brain was scanned at 9.4T using a PTx multi-echo and single-echo GRE at 200/100μm. Cerebellar grey/white matter was segmented with a cerebellum-specific segmentation pipeline. Results: In the resulting segmentations, white matter branches were longer and more continuous in the 100μm data, compared to the 200μm data. Surfaces showed finer foliations at higher spatial resolutions. Impact: Improving spatial resolution beyond 200μm improves cerebellar segmentation and brings MRI morphometric measures closer to histology. These results imply that more detailed measures of the human cerebellum may benefit further (clinical) neuroscience studies.