Quantitative susceptibility mapping of brain iron predicts onset of mild cognitive impairment and cognitive decline

Motivation: Brain iron content may play an important role in the development of Mild Cognitive Impairment (MCI) and dementia due to Alzheimer’s Disease (AD). Goal(s): To investigate the utility of baseline brain iron levels, measured by quantitative susceptibility mapping (QSM), to predict time to onset of symptoms of MCI and global cognitive decline among older adults with normal cognition at baseline. Approach: Cox regression models and linear mixed models were used. Results: Higher brain iron levels in entorhinal cortex and putamen were associated with an earlier time to MCI onset and greater global cognitive decline, independent of the volume and amyloid of those regions. Impact: Brain iron deposition assessed by QSM MRI may help predict risk of MCI onset and cognitive decline among cognitively normal individuals.