MRI signatures of white matter and cortical microstructure link to human cognitive impairment and brain risk factors in community elderly cohort

Motivation: The clinical application potential of SANDI is considerable and requires further exploration. We aim to explore the relationship between cognition and microstructural substrates to provide new insights into brain health Goal(s): Investigate the relationship between soma and neurite signal fractions, cognitive function, and brain risk factors in an elderly cohort at risk of dementia Approach: We applied SANDI to 249 elderly individuals with varying cognitive levels using multi-shell dMRI measurements on a 3T Connectome MRI scanner Results: Soma fraction, soma radius, and neurite fraction decreased with declining cognitive function,extra-cellular fraction increased with cognitive impairment Impact: Using SANDI, we analyzed microstructure, particularly soma, in an aging cohort with a high-gradient MRI scanner. A strong correlation was observed between SANDI metrics and brain function decline, which may contribute to the neurodegenerative process