Brain-PACE: A Deep Siamese MRI Framework for Modelling Longitudinal Brain Acceleration

TL;DR - Brain-PACE is a Siamese deep-learning framework that directly estimates structural brain-age acceleration from paired T1-weighted MRI. Its stronger associations with cognitive impairment and regional tau burden suggest it may provide a useful longitudinal imaging marker for early neurodegeneration.

• Brain-PACE detected accelerated ageing in 42.6% of participants with mild cognitive impairment.
• Faster estimated ageing correlated with worse functional and cognitive scores, including FAQ ($r=0.35$), ADAS13 ($r=0.30$), and CDR-SB ($r=0.32$).
• It was associated with tau burden in the posterior cingulate ($r=0.59$), precuneus ($r=0.47$), and entorhinal cortex ($r=0.37$).
• The framework extends LILAC with spatial attention, soft label distributions, and a Cramér-distance objective to reduce bias and provide predictive uncertainty.