The Brainstem Navigator atlas in in-vivo elderly adults by 7 Tesla multi-contrast MRI

Motivation: A probabilistic atlas of brainstem nuclei in elderly living humans is unavailable. Goal(s): To develop an in-vivo probabilistic atlas of 31 brainstem and three diencephalic nuclei in elderly healthy humans using multi-contrast (diffusion/ T2-weighted) 7 Tesla MRI. Approach: After preprocessing and coregistration to stereotactic space (MIITRAv2), manual delineation of nuclei labels was performed, and validated using internal consistency, signal inhomogeneity and volume assessment. Results: This atlas can be applied to conventional MRI and aid brainstem research in aging. The deformations in neurofluid spaces and gene expressions of specific brain cells correlated with morphological deformations of brainstem/diencephalic nuclei with aging. Impact: This atlas will facilitate brainstem related research in health and a broad set of brainstem related disorders, such as sleep, arousal, movement, vestibular, anxiety disorders, which is currently limited by the difficulty of localizing brainstem nuclei in conventional MRI.